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C语言经典程序100例

时间:2018-10-04 10:59:05      阅读:165      评论:0      收藏:0      [点我收藏+]

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 --------------------------------------------------------------------------------

【程序1】

题目:古典问题:有一对兔子,从出生后第3个月起每个月都生一对兔子,小兔子长到第三个月

   后每个月又生一对兔子,假如兔子都不死,问每个月的兔子总数为多少?

1.程序分析: 兔子的规律为数列1,1,2,3,5,8,13,21....

2.程序源代码:

#include<stdio.h>

void main(){

         long f1,f2;                                     //前两个月的兔子数

         f1=f2=1;

         for(int i=1;i<=20;i++){                         //i为月份

                   printf("%12ld %12ld ",f1,f2);

                   if(i%2==0) printf("\n");              //每行输出4个

                   f1=f1+f2;                   //前两个月加起来赋值给第三个月

                   f2=f2+f1;

         }

}

/*

           1            1            2            3

           5            8           13           21

          34           55           89          144

         233          377          610          987

        1597         2584         4181         6765

       10946        17711        28657        46368

       75025       121393       196418       317811

      514229       832040      1346269      2178309

     3524578      5702887      9227465     14930352

    24157817     39088169     63245986    102334155

Press any key to continue

*/

==============================================================

【程序2】

题目:判断101-200之间有多少个素数,并输出所有素数。

1.程序分析:判断素数的方法:用一个数分别去除2到sqrt(这个数),如果能被整除,

      则表明此数不是素数,反之是素数。       

2.程序源代码:

#include<stdio.h>

#include<math.h>

void main(){

         int k=0,leap=1;

         for(int n=101;n<=200;n++){              //101--200

                   for(int i=2;i<=sqrt(n);i++){         //2--sqrt(i)

                            if(n%i==0){

                                     leap=0;

                                     break;

                            }

                   }

                   if(leap){

                            printf("%-4d",n);

                            k++;

                            if(k%10==0) printf("\n");

                   }

                   leap=1;

         }

         printf("\nThe total is %d\n",k);

}

/*

101 103 107 109 113 127 131 137 139 149

151 157 163 167 173 179 181 191 193 197

199

The total is 21

Press any key to continue

*/

==============================================================

【程序3】

题目:打印出所有的“水仙花数”,所谓“水仙花数”是指一个三位数,其各位数字立方和等于该数

   本身。例如:153是一个“水仙花数”,因为153=1的三次方+5的三次方+3的三次方。

1.程序分析:利用for循环控制100-999个数,每个数分解出个位,十位,百位。

2.程序源代码:

#include<stdio.h>

void main(){

         int a,b,c;

         int n;

         printf("water flower‘munber is: ");

         for(n=100;n<=999;n++){

                   a=n/100;  //百位

                   b=n%100/10;   //十位

                   c=n%10;            //个位

                   if(n=a*a*a+b*b*b+c*c*c){

                            printf("%5d ",n);

                   }

         }

         printf("\n");

}

/*

water flower‘munber is:     1     8   729   370   371   378  1099

Press any key to continue

*/

==============================================================

【程序4】

题目:将一个正整数分解质因数。例如:输入90,打印出90=2*3*3*5。

程序分析:对n进行分解质因数,应先找到一个最小的质数k,然后按下述步骤完成:

(1)如果这个质数恰等于n,则说明分解质因数的过程已经结束,打印出即可。

(2)如果n<>k,但n能被k整除,则应打印出k的值,并用n除以k的商,作为新的正整数你n,

 重复执行第一步。

(3)如果n不能被k整除,则用k+1作为k的值,重复执行第一步。

2.程序源代码:

#include<stdio.h>

void main(){

         int n;

         printf("Please input a number: ");

         scanf("%d",&n);

         printf("%d= ",n);

         for(int i=2;i<=n;i++){

                   while(n!=i){

                            if(n%i==0){

                                     printf("%d * ",i);

                                     n=n/i;

                            }else

                                     break;

                   }

         }

         printf("%d",n);

         printf("\n");

}

/*

Please input a number: 90

90= 2 * 3 * 3 * 5

Press any key to continue

*/

==============================================================

【程序5】

题目:利用条件运算符的嵌套来完成此题:学习成绩>=90分的同学用A表示,60-89分之间的用B表示,

   60分以下的用C表示。

1.程序分析:(a>b)?a:b这是条件运算符的基本例子。

2.程序源代码:

#include<stdio.h>

void main(){

         int score;

         char grade;

         printf("Please input a score: ");

         scanf("%d",&score);

         grade=score>=90?‘A‘:(score>=60?‘B‘:‘C‘);

         printf("%d belongs to %c \n",score,grade);

}

/*

Please input a score: 91

91 belongs to A

Press any key to continue

 

Please input a score: 87

87 belongs to B

Press any key to continue

 

Please input a score: 50

50 belongs to C

Press any key to continue

*/

==============================================================

【程序6】

题目:输入两个正整数m和n,求其最大公约数和最小公倍数。

1.程序分析:利用辗除法。

2.程序源代码:

#include<stdio.h>

void main(){

         int m,n,temp,a,b;

         printf("Please input two numbers: ");

         scanf("%d %d",&m,&n);

         if(m<n){

                   temp=m;

                   m=n;

                   n=temp;

         }

         a=m;

         b=n;

         while(b!=0){

                   temp=a%b;

                   a=b;

                  b=temp;

         }

         printf("最大公约数为:%d\n",a);

         printf("最小公倍数为:%d\n",n*m/a);

}

/*

Please input two numbers: 12 3

最大公约数为:3

最小公倍数为:12

Press any key to continue

*/

==============================================================

【程序7】

题目:输入一行字符,分别统计出其中英文字母、空格、数字和其它字符的个数。

1.程序分析:利用while语句,条件为输入的字符不为‘\n‘.

2.程序源代码:

#include<stdio.h>

void main(){

         char c;

         int letters=0,space=0,digit=0,others=0;  //字母、空格、数字、其他字符

         printf("Please input some characters\n");

         while((c=getchar())!=‘\n‘){

                   if((c>=‘a‘&&c<=‘z‘)||(c>=‘A‘&&c<=‘Z‘))

                            letters++;

                   else if(c==‘ ‘)

                            space++;

                   else if(c>=‘0‘&&c<=‘9‘)

                            digit++;

                   else

                            others++;

         }

         printf("all in all: English letters=%d space=%d digit=%d others=%d\n",letters,space,digit,others);

}

/*

Please input some characters

QJ3409V3O TEU40T93EJT934 34erj%j*a4

all in all: English letters=16 space=2 digit=15 others=2

Press any key to continue

*/

==============================================================

【程序8】

题目:求s=a+aa+aaa+aaaa+aa...a的值,其中a是一个数字。例如2+22+222+2222+22222(此时

   共有5个数相加),几个数相加有键盘控制。

1.程序分析:关键是计算出每一项的值。

2.程序源代码:

#include<stdio.h>

void main(){

         int a,n,count=1;   //数字a,n个数相加

         long sn=0,tn=0;

         printf("Please input a and n: ");

         scanf("%d %d",&a,&n);

         printf("a=%d,n=%d\n",a,n);

         while(count<=n){

                   tn=tn+a;

                   sn=sn+tn;

                   a=a*10;

                   ++count;

         }

         printf("a+aa+...=%d\n",sn);

}

/*

Please input a and n: 3 4

a=3,n=4

a+aa+...=3702

Press any key to continue

*/

==============================================================

【程序9】

题目:一个数如果恰好等于它的因子之和,这个数就称为“完数”。例如6=1+2+3.编程

   找出1000以内的所有完数。

1. 程序分析:请参照程序<--上页程序14.

2.程序源代码:

#include<stdio.h>

void main(){

         int k[10];

         int n,s,i,m;

         for(n=2;n<1000;n++){

                   i=-1;

                   s=n;

                   for(m=1;m<n;m++){

                            if(n%m==0){

                                     i++;

                                     s=s-m;

                                     k[i]=m;

                            }

                   }

                   if(s==0){

                            printf("%d is a wanshu\n",n);

                   }

         }

}

/*

6 is a wanshu

28 is a wanshu

496 is a wanshu

Press any key to continue

*/

main()

{

static int k[10];

int i,j,n,s;

for(j=2;j<1000;j++)

 {

 n=-1;

 s=j;

  for(i=1;i   {

   if((j%i)==0)

   { n++;

    s=s-i;

    k[n]=i;

   }

  }

 if(s==0)

 {

 printf("%d is a wanshu",j);

 for(i=0;i  printf("%d,",k[i]);

 printf("%d\n",k[n]);

 }

}

}

==============================================================

【程序10】

题目:一球从100米高度自由落下,每次落地后反跳回原高度的一半;再落下,求它在

   第10次落地时,共经过多少米?第10次反弹多高?

1.程序分析:见下面注释

2.程序源代码:

#include<stdio.h>

void main(){

         float sn=100.0,hn=sn/2;

         int n;

         for(n=2;n<=10;n++){

                   sn=sn+2*hn;              //第n次落地时共经过的米数

                   hn=sn/2;            //第n次反弹高度

         }

         printf("the total of road is %f \n",sn);

         printf("the tenth is %f meters\n",hn);

}

/*

the total of road is 51200.000000

the tenth is 25600.000000 meters

Press any key to continue

*/

=============================================================

【程序11】

题目:有1、2、3、4个数字,能组成多少个互不相同且无重复数字的三位数?都是多少?

1.程序分析:可填在百位、十位、个位的数字都是1、2、3、4。组成所有的排列后再去掉不满足条件的排列。

2.程序源代码:

#include<stdio.h>

void main(){

         int i,j,k;

         int n=0;

         for(i=1;i<=4;i++){  //以下为三重循环

                   for(j=1;j<=4;j++){

                            for(k=1;k<=4;k++){

                                     if(i!=j&&j!=k&&i!=k){  //排除i、j、k相同的情况

                                               printf("%d,%d,%d     ",i,j,k);

                                               printf("the number is %d%d%d\n",i,j,k);

                                               n++;

                                     }

                            }

                   }

         }

         printf("\nA total of number is %d\n",n);

}

/*

1,2,3     the number is 123

1,2,4     the number is 124

1,3,2     the number is 132

1,3,4     the number is 134

1,4,2     the number is 142

1,4,3     the number is 143

2,1,3     the number is 213

2,1,4     the number is 214

2,3,1     the number is 231

2,3,4     the number is 234

2,4,1     the number is 241

2,4,3     the number is 243

3,1,2     the number is 312

3,1,4     the number is 314

3,2,1     the number is 321

3,2,4     the number is 324

3,4,1     the number is 341

3,4,2     the number is 342

4,1,2     the number is 412

4,1,3     the number is 413

4,2,1     the number is 421

4,2,3     the number is 423

4,3,1     the number is 431

4,3,2     the number is 432

 

A total of number is 24

Press any key to continue

*/

==============================================================

【程序12】

题目:企业发放的奖金根据利润提成。利润(I)低于或等于10万元时,奖金可提10%;利润高于10万元,低于20万元时,低于10万元的部分按10%提成,高于10万元的部分,可可提成7.5%;20万到40万之间时,高于20万元的部分,可提成5%;40万到60万之间时高于40万元的部分,可提成3%;60万到100万之间时,高于60万元的部分,可提成1.5%,高于100万元时,超过100万元的部分按1%提成,从键盘输入当月利润I,求应发放奖金总数?

1.程序分析:请利用数轴来分界,定位。注意定义时需把奖金定义成长整型。      

2.程序源代码:

#include<stdio.h>

void main(){

         long int i;

         int bonus1,bonus2,bonus4,bonus6,bonus10,bonus;

         printf("Please input the profit I:");

         scanf("%ld",&i);

         bonus1=100000*0.1;

         bonus2=bonus1+100000*0.075;

         bonus4=bonus2+200000*0.05;

         bonus6=bonus4+200000*0.03;

         bonus10=bonus6+400000*0.015;

         if(i<=100000)

                   bonus=i*0.1;

         else if(i<=200000)

                   bonus=bonus1+(i-100000)*0.075;

         else if(i<=400000)

                   bonus=bonus2+(i-200000)*0.05;

         else if(i<=600000)

                   bonus=bonus4+(i-400000)*0.03;

         else if(i<=1000000)

                   bonus=bonus6+(i-600000)*0.015;

         else

                   bonus=bonus10+(i-1000000)*0.01;

         printf("bonus=%d\n",bonus);

}

/*

Please input the profit I:340000

bonus=24500

Press any key to continue

*/

==============================================================

【程序13】

题目:一个整数,它加上100后是一个完全平方数,再加上168又是一个完全平方数,请问该数是多少?

1.程序分析:在10万以内判断,先将该数加上100后再开方,再将该数加上268后再开方,如果开方后的结果满足如下条件,即是结果。请看具体分析:

2.程序源代码:

#include<stdio.h>

#include<math.h>

void main(){

         long int i,x,y;

         for(i=1;i<100000;i++){

                   x=sqrt(i+100);//x为加上100后开方后的结果

                   y=sqrt(i+268);//y为再加上168后开方后的结果

                   if(x*x==i+100&&y*y==i+268)//如果一个数的平方根的平方等于该数,这说明此数是完全平方数

                            printf("the number is %ld\n",i);

         }

}

/*

the number is 21

the number is 261

the number is 1581

Press any key to continue

*/

==============================================================

【程序14】

题目:输入某年某月某日,判断这一天是这一年的第几天?

1.程序分析:以3月5日为例,应该先把前两个月的加起来,然后再加上5天即本年的第几天,特殊情况,闰年且输入月份大于3时需考虑多加一天。

2.程序源代码:

#include<stdio.h>

void main(){

         int day,month,year,sum,leap;

         printf("Please input year,month,day: ");

         scanf("%d %d %d",&year,&month,&day);

         switch(month){ //先计算某月以前月份的总天数

                   case 1:sum=0;break;

                   case 2:sum=31;break;

                   case 3:sum=59;break;

                   case 4:sum=90;break;

                   case 5:sum=120;break;

                   case 6:sum=151;break;

                   case 7:sum=181;break;

                   case 8:sum=212;break;

                   case 9:sum=243;break;

                   case 10:sum=273;break;

                   case 11:sum=304;break;

                   case 12:sum=334;break;

                   default:printf("data error");break;

         }

         sum=sum+day;  //再加上某天的天数

         if((year%4==0&&year%100!=0)||(year%400==0)) //判断是否是闰年

                   leap=1;

         else

                   leap=0;

         if(leap==1&&month>2)     //如果是闰年且月份大于2,总天数应该加一天

                   sum++;

         printf("It is the %dth day.\n",sum);

}

/*

Please input year,month,day: 2019 3 1

It is the 60th day.

Press any key to continue

*/

==============================================================

【程序15】

题目:输入三个整数x,y,z,请把这三个数由小到大输出。

1.程序分析:我们想办法把最小的数放到x上,先将x与y进行比较,如果x>y则将x与y的值进行交换,然后再用x与z进行比较,如果x>z则将x与z的值进行交换,这样能使x最小。

2.程序源代码:

#include<stdio.h>

void main(){

         int x,y,z,temp;

         printf("Please input three numbers:");

         scanf("%d %d %d",&x,&y,&z);

         if (x>y){   //交换x,y的值

                   temp=x;

                  x=y;

                   y=temp;

         }

         if(x>z){     //交换x,z的值

                   temp=x;

                   x=z;

                   z=temp;

         }

         if(y>z){     //交换z,y的值

                   temp=y;

                   y=z;

                   z=temp;

         }

         printf("small to big: %d %d %d\n",x,y,z);

}

/*

Please input three numbers:34 13 23

small to big: 13 23 34

Press any key to continue

*/

==============================================================

【程序16】

题目:用*号输出字母C的图案。

1.程序分析:可先用‘*‘号在纸上写出字母C,再分行输出。

2.程序源代码:

#include <stdio.h>

void main(){

         printf("Hello C-world!\n");

         printf(" ****\n");

         printf(" *\n");

         printf(" * \n");

         printf(" ****\n");

}

/*

Hello C-world!

 ****

 *

 *

 ****

Press any key to continue

*/

==============================================================

【程序17】

题目:输出特殊图案,请在c环境中运行,看一看,Very Beautiful!

1.程序分析:字符共有256个。不同字符,图形不一样。      

2.程序源代码:

#include <stdio.h>

void main(){

         char a=32,b=64;

         printf("%c%c%c%c%c\n",b,a,a,a,b);

         printf("%c%c%c%c%c\n",a,b,a,b,a);

         printf("%c%c%c%c%c\n",a,a,b,a,a);

         printf("%c%c%c%c%c\n",a,b,a,b,a);

         printf("%c%c%c%c%c\n",b,a,a,a,b);

}

/*

@   @

 @ @

  @

 @ @

@   @

Press any key to continue

*/

==============================================================

【程序18】

题目:输出9*9口诀。

1.程序分析:分行与列考虑,共9行9列,i控制行,j控制列。

2.程序源代码:

#include <stdio.h>

void main(){

         int i,j,result;

         for (i=1;i<=9;i++){

                   for(j=1;j<=9;j++){

                            result=i*j;

                            printf("%d*%d=%-3d",i,j,result);//-3d表示左对齐,占3位

                   }

                   printf("\n"); //每一行后换行

         }

}

/*

1*1=1  1*2=2  1*3=3  1*4=4  1*5=5  1*6=6  1*7=7  1*8=8  1*9=9

2*1=2  2*2=4  2*3=6  2*4=8  2*5=10 2*6=12 2*7=14 2*8=16 2*9=18

3*1=3  3*2=6  3*3=9  3*4=12 3*5=15 3*6=18 3*7=21 3*8=24 3*9=27

4*1=4  4*2=8  4*3=12 4*4=16 4*5=20 4*6=24 4*7=28 4*8=32 4*9=36

5*1=5  5*2=10 5*3=15 5*4=20 5*5=25 5*6=30 5*7=35 5*8=40 5*9=45

6*1=6  6*2=12 6*3=18 6*4=24 6*5=30 6*6=36 6*7=42 6*8=48 6*9=54

7*1=7  7*2=14 7*3=21 7*4=28 7*5=35 7*6=42 7*7=49 7*8=56 7*9=63

8*1=8  8*2=16 8*3=24 8*4=32 8*5=40 8*6=48 8*7=56 8*8=64 8*9=72

9*1=9  9*2=18 9*3=27 9*4=36 9*5=45 9*6=54 9*7=63 9*8=72 9*9=81

Press any key to continue

*/

==============================================================

【程序19】

题目:要求输出国际象棋棋盘。

1.程序分析:用i控制行,j来控制列,根据i+j的和的变化来控制输出黑方格,还是白方格。

2.程序源代码:

#include<stdio.h>

void main(){

         int i,j;

         for(i=0;i<8;i++){

                   for(j=0;j<8;j++){

                            if((i+j)%2==0)

                                     printf("%c%c",219,219);

                            else

                                     printf(" ");

                   }

                   printf("\n");

         }

}

/*圹 圹 圹 圹

 圹 圹 圹 圹

圹 圹 圹 圹

 圹 圹 圹 圹

圹 圹 圹 圹

 圹 圹 圹 圹

圹 圹 圹 圹

 圹 圹 圹 圹

Press any key to continue

*/

==============================================================

【程序20】

题目:打印楼梯,同时在楼梯上方打印两个笑脸。

1.程序分析:用i控制行,j来控制列,j根据i的变化来控制输出黑方格的个数。

2.程序源代码:

#include<stdio.h>

void main(){

         int i,j;

         printf("\1\1\n"); //输出两个笑脸

         for(i=1;i<11;i++){

                   for(j=1;j<=i;j++){

                            printf("%c%c",219,219);

                   }

                   printf("\n");

         }

}

/*

..

圹圹

圹圹圹

圹圹圹圹

圹圹圹圹圹

圹圹圹圹圹圹

圹圹圹圹圹圹圹

圹圹圹圹圹圹圹圹

圹圹圹圹圹圹圹圹圹

圹圹圹圹圹圹圹圹圹圹

Press any key to continue

*/

============================================================

【程序21】

题目:猴子吃桃问题:猴子第一天摘下若干个桃子,当即吃了一半,还不瘾,又多吃了一个

   第二天早上又将剩下的桃子吃掉一半,又多吃了一个。以后每天早上都吃了前一天剩下

   的一半零一个。到第10天早上想再吃时,见只剩下一个桃子了。求第一天共摘了多少。

1.程序分析:采取逆向思维的方法,从后往前推断。

2.程序源代码:

#include<stdio.h>

void main(){

         int day,x1,x2=1;

         for(day=9;day>0;day--){

                   x1=(x2+1)*2;  //第一天的桃子数是第2天桃子数加1后的2倍

                   x2=x1;

         }

         printf("the total is %d\n",x1);

}

/*

the total is 1534

Press any key to continue

*/

==============================================================

【程序22】

题目:两个乒乓球队进行比赛,各出三人。甲队为a,b,c三人,乙队为x,y,z三人。已抽签决定

   比赛名单。有人向队员打听比赛的名单。a说他不和x比,c说他不和x,z比,请编程序找出

   三队赛手的名单。

1.程序分析:判断素数的方法:用一个数分别去除2到sqrt(这个数),如果能被整除,

      则表明此数不是素数,反之是素数。       

2.程序源代码:

#include<stdio.h>

void main(){

         char i,j,k;  //i是a的对手,j是b的对手,k是c的对手

         for(i=‘x‘;i<=‘z‘;i++){

                   for(j=‘x‘;j<=‘z‘;j++){

                            if(i!=j){

                                     for(k=‘x‘;k<=‘z‘;k++){

                                               if(i!=k&&j!=k){

                                                        if(i!=‘x‘&&k!=‘x‘&&k!=‘z‘)

                                                                 printf("order is a--%c\tb--%c\tc--%c\n",i,j,k);

                                               }

                                     }

                            }

                   }

         }

}

/*

order is a--z   b--x    c--y

Press any key to continue

*/

==============================================================

【程序23】

题目:打印出如下图案(菱形)

 

*

***

******

********

******

***

*

1.程序分析:先把图形分成两部分来看待,前四行一个规律,后三行一个规律,利用双重

      for循环,第一层控制行,第二层控制列。

2.程序源代码:

#include<stdio.h>

void main(){

         int i,j,k;

         for(i=0;i<=3;i++){

                   for(j=0;j<=2-i;j++){

                            printf(" ");

                   }

                   for(k=0;k<=2*i;k++){

                            printf("*");

                   }

                   printf("\n");

         }

         for(i=0;i<=2;i++){

                   for(j=0;j<=i;j++){

                            printf(" ");

                   }

                   for(k=0;k<=4-2*i;k++){

                            printf("*");

                   }

                   printf("\n");

         }

}

/*

   *

  ***

 *****

*******

 *****

  ***

   *

Press any key to continue

*/

==============================================================

【程序24】

题目:有一分数序列:2/1,3/2,5/3,8/5,13/8,21/13...求出这个数列的前20项之和。

1.程序分析:请抓住分子与分母的变化规律。

2.程序源代码:

#include<stdio.h>

void main(){

         int n,t;

         float a=2,b=1,s=0;

         for(n=1;n<=20;n++){

                   s=s+a/b;

                   t=a;

                   a=a+b;

                   b=t;

         }

         printf("sum is %9.6f\n",s);

}

/*

sum is 32.660259

Press any key to continue

*/

==============================================================

【程序25】

题目:求1+2!+3!+...+20!的和

1.程序分析:此程序只是把累加变成了累乘。

2.程序源代码:

#include<stdio.h>

void main(){

         float n,s=0,t=1;

         for(n=1;n<=20;n++){

                   t*=n;

                   s+=t;

         }

         printf("1+2!+3!...+20!=%e\n",s);

}

/*

1+2!+3!...+20!=2.561327e+018

Press any key to continue

*/

==============================================================

【程序26】

题目:利用递归方法求5!。

1.程序分析:递归公式:fn=fn_1*4!

2.程序源代码:

#include<stdio.h>

int fact(int j){

         int sum;

         if(j==0)

                   sum=1;

         else

                   sum=j*fact(j-1);

         return sum;

}

void main(){

         int i;

         int fact(int);

         for(i=0;i<6;i++)

                   printf(" %d!=%d\n",i,fact(i));

}

/*

 0!=1

 1!=1

 2!=2

 3!=6

 4!=24

 5!=120

Press any key to continue

*/

==============================================================

【程序27】

题目:利用递归函数调用方式,将所输入的5个字符,以相反顺序打印出来。

1.程序分析:

2.程序源代码:

#include<stdio.h>

void main(){

         int i=5;

         void palin(int n);

         printf("Please input five characters: ");

         palin(i);

         printf("\n");

}

void palin(int n){

         char next;

         if(n<=1){

                   next=getchar();

                   printf("the opposite characters is: ");

                   putchar(next);

         }

         else{

                   next=getchar();

                   palin(n-1);

                   putchar(next);

         }

}

/*

Please input five characters: rterd

the opposite characters is: dretr

Press any key to continue

*/

==============================================================

【程序28】

题目:有5个人坐在一起,问第五个人多少岁?他说比第4个人大2岁。问第4个人岁数,他说比第

   3个人大2岁。问第三个人,又说比第2人大两岁。问第2个人,说比第一个人大两岁。最后

   问第一个人,他说是10岁。请问第五个人多大?

1.程序分析:利用递归的方法,递归分为回推和递推两个阶段。要想知道第五个人岁数,需知道

      第四人的岁数,依次类推,推到第一人(10岁),再往回推。

2.程序源代码:

#include<stdio.h>

age(int n){

         int c;

         if(n==1)

                   c=10;

         else

                   c=age(n-1)+2;

         return c;

}

void main(){

         printf("the age of the five is: %d\n",age(5));

}

/*

the age of the five is: 18

Press any key to continue

*/

==============================================================

【程序29】

题目:给一个不多于5位的正整数,要求:一、求它是几位数,二、逆序打印出各位数字。

1. 程序分析:学会分解出每一位数,如下解释:(这里是一种简单的算法,师专数002班赵鑫提供)

2.程序源代码:

#include<stdio.h>

void main( ){

         long a,b,c,d,e,x;

         printf("Please input the number: ");

         scanf("%ld",&x);

         a=x/10000;                //分解出万位

         b=x%10000/1000;   //分解出千位

         c=x%1000/100;                 //分解出百位

         d=x%100/10;            //分解出十位

         e=x%10;            //分解出个位

         if (a!=0)

                   printf("there are 5,  %ld %ld %ld %ld %ld\n",e,d,c,b,a);

         else if (b!=0)

                   printf("there are 4,  %ld %ld %ld %ld\n",e,d,c,b);

         else if (c!=0)

                   printf("there are 3,  %ld %ld %ld\n",e,d,c);

         else if (d!=0)

                   printf("there are 2,  %ld %ld\n",e,d);

         else if (e!=0)

                   printf("there are 1, %ld\n",e);

}

/*

Please input the number: 23458

there are 5,  8 5 4 3 2

Press any key to continue

*/

==============================================================

【程序30】

题目:一个5位数,判断它是不是回文数。即12321是回文数,个位与万位相同,十位与千位相同。   

1.程序分析:同29例

2.程序源代码:

#include<stdio.h>

void main( ){

         long ge,shi,qian,wan,x;

         printf("Please input a number: ");

         scanf("%ld",&x);

         wan=x/10000;

         qian=x%10000/1000;

         shi=x%100/10;

         ge=x%10;

         if (ge==wan&&shi==qian)  //个位等于万位并且十位等于千位

                   printf("this number is a huiwen.\n");

         else

                   printf("this number is not a huiwen.\n");

}

/*

Please input a number: 24542

this number is a huiwen.

Press any key to continue

*/

=============================================================

【程序31】

题目:请输入星期几的第一个字母来判断一下是星期几,如果第一个字母一样,则继续判断第二个字母。

1.程序分析:用情况语句比较好,如果第一个字母一样,则判断用情况语句或if语句判断第二个字母。

2.程序源代码:

#include <stdio.h>

void main(){

         char letter1,letter2;

         printf("please input the first letter of someday: ");

         scanf("%c",&letter1);

         getchar();

         switch (letter1){

                   case ‘M‘:printf("Monday\n");break;

                   case ‘W‘:printf("Wednesday\n");break;

                   case ‘F‘:printf("Friday\n");break;

                   case ‘S‘:

                            printf("please input the second letter: ");

                            if((letter2=getchar())==‘a‘)

                                     printf("Saturday\n");

                            else if((letter2=getchar())==‘u‘)

                                     printf("Sunday\n");

                            else

                                     printf("data error\n");

                            break;

                   case ‘T‘:

                            printf("please input second letter: ");

                            if((letter2=getchar())==‘u‘)

                                     printf("Tuesday\n");

                            else if((letter2=getchar())==‘h‘)

                                     printf("Thursday\n");

                            else

                                     printf("data error\n");

                            break;

                   default: printf("data error\n");

         }

}

/*

please input the first letter of someday: S

please input the second letter: a

Saturday

Press any key to continue

*/

#include <stdio.h>

void main()

{

char letter;

printf("please input the first letter of someday\n");

while ((letter=getch())!=‘Y‘)/*当所按字母为Y时才结束*/

{ switch (letter)

{case ‘S‘:printf("please input second letter\n");

     if((letter=getch())==‘a‘)

      printf("saturday\n");

     else if ((letter=getch())==‘u‘)

         printf("sunday\n");

       else printf("data error\n");

     break;

case ‘F‘:printf("friday\n");break;

case ‘M‘:printf("monday\n");break;

case ‘T‘:printf("please input second letter\n");

     if((letter=getch())==‘u‘)

      printf("tuesday\n");

     else if ((letter=getch())==‘h‘)

         printf("thursday\n");

       else printf("data error\n");

     break;

case ‘W‘:printf("wednesday\n");break;

default: printf("data error\n");

  }

 }

}

==============================================================

【程序32】

题目:Press any key to change color, do you want to try it. Please hurry up!

1.程序分析:

textbackground() 文本背景函数

功能: 函数textbackground()设置字符屏幕下文本背景颜色(或字符背景颜色)。

用法: 此函数调用方式为void textbackground(int bcolor);

说明: 参数bcolor 的有效值取表1-4背景颜色(即宏名)或等价值。

表1-4 背景颜色与等价值

-------------------------------------------------

  背景颜色 等价值 含 义

-------------------------------------------------

  BLACK 0 黑

  BLUE 1 蓝

  GREEN 2 绿

  CYAN 3 青

  RED 4 红

  MAGENTA 5 洋红

  BROWN 6 棕

-------------------------------------------------

调用该函数只影响后续写的字符背景颜色,而不改变当前显示在屏幕上的字符背景颜色。

  这个函数对应的头文件是conio.h

返回值: 无

例: 设置文本背景颜色为蓝色:

  textbackground(BLUE));

 

[我的疑问]:

1 我该如何做才能实现“Press any key to change color”的功能;

2 在VC++6.0中运行,这种颜色变化在哪可以体现呢?

3 textbackground(BLUE));

[解决方案]

这个TC是支持的GDI,你放VC上跑有什么用

[解决方案]

vc6.0不支持TC下的图形相关的编程的,像#include都是不行的。

如果非要用,考虑boost库(但非标准库,需另行安装!)

转            

2.程序源代码:

#include <conio.h>

#include <stdio.h>

void main(){

         int color;

         for(color=0;color<8;color++){

                   textbackground(color);//设置文本的背景颜色

                   cprintf("This is color %d\n",color);

                   cprintf("Press any key to continue\r\n");

                   getchar();  //输入字符看不见

         }

}

==============================================================

【程序33】

题目:学习gotoxy()与clrscr()函数

1.程序分析:

2.程序源代码:

#include <conio.h>

void main(){

         clrscr();               //清屏函数

         textbackground(2);

         gotoxy(1, 5);     //定位函数

         cprintf("Output at row 5 column 1\n");

         textbackground(3);

         gotoxy(20, 10);

         cprintf("Output at row 10 column 20\n");

}

==============================================================

【程序34】

题目:练习函数调用

1. 程序分析:

2.程序源代码:

#include <stdio.h>

void hello_world(void){

         printf("Hello, world!\n");

}

void three_hellos(void){

         int counter;

         for (counter = 1; counter <= 3; counter++)

                   hello_world();  //调用此函数

}

void main(void){

         three_hellos();            //调用此函数

}

/*

Hello, world!

Hello, world!

Hello, world!

Press any key to continue

*/

==============================================================

【程序35】

题目:文本颜色设置

1.程序分析:

2.程序源代码:

#include <conio.h>

void main(void){

         int color;

         for (color = 1; color < 16; color++){

                   textcolor(color);  //设置文本颜色

                   cprintf("This is color %d\r\n", color);

         }

         textcolor(128 + 15);

         cprintf("This is blinking\r\n");

}

==============================================================

【程序36】

题目:求100之内的素数   

1.程序分析:

2.程序源代码:

#include <stdio.h>

#include <math.h>

#define N 101

void main(){

         int i,j,line,a[N];

         for(i=2;i<N;i++)

                   a[i]=i;

         for(i=2;i<sqrt(N);i++){

                   for(j=i+1;j<N;j++){

                            if(a[i]!=0&&a[j]!=0&&a[j]%a[i]==0)

                                     a[j]=0;

                   }

         }

         for(i=2,line=0;i<N;i++){

                   if(a[i]!=0){

                            printf("%5d",a[i]);

                            line++;

                   }

                   if(line==10){    //十个数换行

                            printf("\n");

                            line=0;

                   }

         }

         printf("\n");

}

/*

    2    3    5    7   11   13   17   19   23   29

   31   37   41   43   47   53   59   61   67   71

   73   79   83   89   97

Press any key to continue

*/

==============================================================

【程序37】

题目:对10个数进行排序

1.程序分析:可以利用选择法,即从后9个比较过程中,选择一个最小的与第一个元素交换,

      下次类推,即用第二个元素与后8个进行比较,并进行交换。       

2.程序源代码:

#include <stdio.h>

#define N 10

void main(){

         int i,j,min,tem,a[N];

         /*input data*/

         printf("please input ten number: \n");

         for(i=0;i<N;i++){

                   scanf("%d",&a[i]);

         }

         printf("\n");

         printf("before sorted \n");

         for(i=0;i<N;i++)

                   printf("%5d",a[i]);

         printf("\n");

         /*sort ten num*/

         for(i=0;i<N-1;i++){

                   min=i;

                   for(j=i+1;j<N;j++)

                            if(a[min]>a[j])

                                     min=j;

                   tem=a[i];

                   a[i]=a[min];

                   a[min]=tem;

         }

         /*output data*/

         printf("After sorted \n");

         for(i=0;i<N;i++)

                   printf("%5d",a[i]);

         printf("\n");

}

/*

please input ten number:

5 4 8 7 0 9 4 6 2 1

 

before sorted

    5    4    8    7    0    9    4    6    2    1

After sorted

    0    1    2    4    4    5    6    7    8    9

Press any key to continue

*/

==============================================================

【程序38】

题目:求一个3*3矩阵对角线元素之和

1.程序分析:利用双重for循环控制输入二维数组,再将a[i][i]累加后输出。

2.程序源代码:

#include <stdio.h>

void main(){

         float a[3][3],sum=0;

         int i,j;

         printf("please input rectangle element: \n");

         for(i=0;i<3;i++)

                   for(j=0;j<3;j++)

                            scanf("%f",&a[i][j]);

         for(i=0;i<3;i++)

                   sum=sum+a[i][i];

         printf("The sum of duijiaoxian is %6.2f.\n",sum);

}

/*

please input rectangle element:

6 5 4 8 7 9 3 0 1 2

The sum of duijiaoxian is  14.00.

Press any key to continue

*/

==============================================================

【程序39】

题目:有一个已经排好序的数组。现输入一个数,要求按原来的规律将它插入数组中。

1. 程序分析:首先判断此数是否大于最后一个数,然后再考虑插入中间的数的情况,插入后

     此元素之后的数,依次后移一个位置。

2.程序源代码:

#include <stdio.h>

void main(){

         int a[11]={1,4,6,9,13,16,19,28,40,100};

         int temp1,temp2,number,end,i,j;

         printf("original array is: \n");

         for(i=0;i<10;i++)

                   printf("%5d",a[i]);

         printf("\n");

         printf("insert a new number: ");

         scanf("%d",&number);

         end=a[9];

         if(number>end)

                   a[10]=number;

         else{

                   for(i=0;i<10;i++){

                            if(a[i]>number){

                                     temp1=a[i];

                                     a[i]=number;

                                     for(j=i+1;j<11;j++){

                                               temp2=a[j];

                                               a[j]=temp1;

                                               temp1=temp2;

                                     }

                                     break;

                            }

                   }

         }

         for(i=0;i<11;i++){

                   printf("%5d",a[i]);

         }

         printf("\n");

}

/*

original array is:

    1    4    6    9   13   16   19   28   40  100

insert a new number: 11

    1    4    6    9   11   13   16   19   28   40  100

Press any key to continue

*/

==============================================================

【程序40】

题目:将一个数组逆序输出。

1.程序分析:用第一个与最后一个交换。

2.程序源代码:

#include <stdio.h>

#define N 10

void main(){

         int a[N]={9,6,5,4,1,8,9,6,4,2},i,temp;

         printf(" original array: \n");

         for(i=0;i<N;i++)

                   printf("%4d",a[i]);

         for(i=0;i<N/2;i++){

                   temp=a[i];

                   a[i]=a[N-i-1];

                   a[N-i-1]=temp;

         }

         printf("\n sorted array: \n");

         for(i=0;i<N;i++)

                   printf("%4d",a[i]);

         printf("\n");

}

/*

 original array:

   9   6   5   4   1   8   9   6   4   2

 sorted array:

   2   4   6   9   8   1   4   5   6   9

Press any key to continue

*/

==============================================================

【程序41】

题目:学习static定义静态变量的用法   

#include <stdio.h>

varfunc(){

         int var=0;

         static int static_var=0;

         printf("\40:var equal %d \n",var);

         printf("\40:static var equal %d \n",static_var);

         printf("\n");

         var++;

         static_var++;

}

void main(){

         int i;

         for(i=0;i<3;i++)

                   varfunc();

}

/*

 :var equal 0

 :static var equal 0

 

 :var equal 0

 :static var equal 1

 

 :var equal 0

 :static var equal 2

 

Press any key to continue

*/

==============================================================

【程序42】

题目:学习使用auto定义变量的用法

2.程序源代码:

#include <stdio.h>

void main(){

         int i,num;

         num=2;

         for (i=0;i<3;i++){

                   printf(" The num equal %d \n",num);

                   num++;

                   {

                            auto int num=1;

                            printf(" The internal block num equal %d\n",num);

                            num++;

                   }

         }

}

/*

 The num equal 2

 The internal block num equal 1

 The num equal 3

 The internal block num equal 1

 The num equal 4

 The internal block num equal 1

Press any key to continue

==============================================================

【程序43】

题目:学习使用static的另一用法。   

2.程序源代码:

#include <stdio.h>

void main(){

         int i,num;

         num=2;

         for(i=0;i<3;i++){

                   printf(" The num equal %d \n",num);

                   num++;

                   {

                            static int num=1;

                            printf(" The internal block num equal %d\n",num);

                            num++;

                   }

         }

}

/*

 The num equal 2

 The internal block num equal 1

 The num equal 3

 The internal block num equal 2

 The num equal 4

 The internal block num equal 3

Press any key to continue

*/

==============================================================

【程序44】

题目:学习使用external的用法。

1.程序分析:

2.程序源代码:

#include <stdio.h>

int a,b,c;

void add(){

         int a;

         a=3;

         c=a+b;

}

void main(){

         a=b=4;

         add();

         printf("The value of c is equal to %d\n",c);

}

/*

The value of c is equal to 7

Press any key to continue

*/

==============================================================

【程序45】

题目:学习使用register定义变量的方法。

1.程序分析:

2.程序源代码:

#include <stdio.h>

void main(){

         register int i;

         int tmp=0;

         for(i=1;i<=100;i++)

                   tmp+=i;

         printf("The sum is %d\n",tmp);

}

==============================================================

【程序46】

题目:宏#define命令练习(1)   

1.程序分析:

2.程序源代码:

#include <stdio.h>

#define TRUE 1

#define FALSE 0

#define SQ(x) (x)*(x)

void main(){

         int num;

         int again=1;

         printf(" Program will stop if input value less than 50.\n");

         while(again){

                   printf(" Please input number==>");

                   scanf("%d",&num);

                   printf(" The square for this number is %d \n",SQ(num));

                   if(num>=50)

                            again=TRUE;

                   else

                            again=FALSE;

         }

}

/*

 Program will stop if input value less than 50.

 Please input number==>54

 The square for this number is 2916

 Please input number==>32

 The square for this number is 1024

Press any key to continue

*/

==============================================================

【程序47】

题目:宏#define命令练习(2)

1.程序分析:            

2.程序源代码:

#include <stdio.h>

#define exchange(a,b){int t;t=a;a=b;b=t;}

void main(){

         int x=10;

         int y=20;

         printf("x=%d; y=%d\n",x,y);

         exchange(x,y);

         printf("x=%d; y=%d\n",x,y);

}

/*

x=10; y=20

x=20; y=10

Press any key to continue

*/

==============================================================

【程序48】

题目:宏#define命令练习(3)   

1.程序分析:

2.程序源代码:

#include <stdio.h>

#define LAG >

#define SMA <

#define EQ ==

#include <stdio.h>

void main(){

         int i=10;

         int j=20;

         if(i LAG j)

                   printf(" %d larger than %d \n",i,j);

         else if(i EQ j)

                   printf(" %d equal to %d \n",i,j);

         else if(i SMA j)

                   printf(" %d smaller than %d \n",i,j);

         else

                   printf(" No such value.\n");

}

/*

 10 smaller than 20

Press any key to continue

*/

==============================================================

【程序49】

题目:#if #ifdef和#ifndef的综合应用。

1. 程序分析:

2.程序源代码:

#include <stdio.h>

#define MAX

#define MAXIMUM(x,y) (x>y)?x:y

#define MINIMUM(x,y) (x>y)?y:x

void main(){

         int a=10,b=20;

         #ifdef MAX

         printf(" The larger one is %d\n",MAXIMUM(a,b));

         #else

         printf(" The lower one is %d\n",MINIMUM(a,b));

         #endif

         #ifndef MIN

         printf(" The lower one is %d\n",MINIMUM(a,b));

         #else

         printf(" The larger one is %d\n",MAXIMUM(a,b));

         #endif

         #undef MAX

         #ifdef MAX

         printf(" The larger one is %d\n",MAXIMUM(a,b));

         #else

         printf(" The lower one is %d\n",MINIMUM(a,b));

         #endif

         #define MIN

         #ifndef MIN

         printf(" The lower one is %d\n",MINIMUM(a,b));

         #else

         printf(" The larger one is %d\n",MAXIMUM(a,b));

         #endif

}

/*

 The larger one is 20

 The lower one is 10

 The lower one is 10

 The larger one is 20

Press any key to continue

*/

3.补充

预编译命令之 if、#if、#ifdef、#ifnde、#undef之间的区别

以#开头的都是预编译指令,就是在正式编译之前,编译器做一些预处理的工作;

一、 if 就是判断语句,不是预编译指令

二、#if

#if 条件语句
程序段1         //如果条件语句成立,那么就编译程序段1  
#endif
程序段2        //如果条件不语句成立,那么就编译程序段2

三、#ifdef

#ifdef x              //先测试x是否被宏定义过  
程序段1            //如果x被宏定义过,那么就编译程序段1  
#endif 
程序段2            //如果x没有被定义过则编译程序段2的语句,“忽视”程序段1。

四、#ifndef
#ifndef x                  //先测试x是否被宏定义过  
#define   程序段1    //如果x没有被宏定义过,那么就编译程序段1   
#endif  
程序段2                   //如果x已经定义过了则编译程序段2的语句,“忽视”程序段1。

五、#undef

#undef x                  //先测试x是否被宏定义过 

#undef 标识符 .其中,标识符是一个宏名称。如果标识符当前没有被定义成一个宏名称,那么就会忽略该指令.一旦定义预处理器标识符,它将保持已定义状态且在作用域内,直到程序结束或者使用#undef 指令取消定义。 

==============================================================

【程序50】

题目:#include 的应用练习   

1.程序分析:

2.程序源代码:

test.h 文件如下:

#define LAG >

#define SMA <

#define EQ ==

#include "test.h" /*一个新文件50.c,包含test.h*/

#include <stdio.h>

void main(){

         int i=10;

         int j=20;

         if(i LAG j)

                   printf("\40: %d larger than %d \n",i,j);

         else if(i EQ j)

                   printf("\40: %d equal to %d \n",i,j);

         else if(i SMA j)

                   printf("\40:%d smaller than %d \n",i,j);

         else

                   printf("\40: No such value.\n");

}

==============================================================

【程序51】

题目:学习使用按位与 & 。   

1.程序分析:0&0=0; 0&1=0; 1&0=0; 1&1=1

2.程序源代码:

#include <stdio.h>

void main(){

         int a,b;

         a=077;

         b=a&3;

         printf(" The a & b(decimal) is %d \n",b);

         b&=7;

         printf(" The a & b(decimal) is %d \n",b);

}

/*

 The a & b(decimal) is 3

 The a & b(decimal) is 3

Press any key to continue

*/

==============================================================

【程序52】

题目:学习使用按位或 | 。

1.程序分析:0|0=0; 0|1=1; 1|0=1; 1|1=1

2.程序源代码:

#include <stdio.h>

void main(){

         int a,b;

         a=077;

         b=a|3;

         printf(" The a & b(decimal) is %d \n",b);

         b|=7;

         printf(" The a & b(decimal) is %d \n",b);

}

/*

 The a & b(decimal) is 63

 The a & b(decimal) is 63

Press any key to continue

*/

==============================================================

【程序53】

题目:学习使用按位异或 ^ 。   

1.程序分析:0^0=0; 0^1=1; 1^0=1; 1^1=0

2.程序源代码:

#include <stdio.h>

void main(){

         int a,b;

         a=077;

         b=a^3;

         printf(" The a & b(decimal) is %d \n",b);

         b^=7;

         printf(" The a & b(decimal) is %d \n",b);

}

/*

 The a & b(decimal) is 60

 The a & b(decimal) is 59

Press any key to continue

*/

==============================================================

【程序54】

题目:取一个整数a从右端开始的4~7位。

程序分析:可以这样考虑:

(1)先使a右移4位。

(2)设置一个低4位全为1,其余全为0的数。可用~(~0<<4)

(3)将上面二者进行&运算。

2.程序源代码:

#include <stdio.h>

void main(){

         unsigned a,b,c,d;

         printf("Please input a number: ");

         scanf("%o",&a);

         b=a>>4;

         c=~(~0<<4);

         d=b&c;

         printf("%o\n%o\n",a,d);

}

/*

Please input a number: 4365476587

43654765

17

Press any key to continue

*/

==============================================================

【程序55】

题目:学习使用按位取反~。   

1.程序分析:~0=1; ~1=0;

2.程序源代码:

#include <stdio.h>

void main(){

         int a,b;

         a=234;

         b=~a;

         printf(" The a‘s 1 complement(decimal) is %d \n",b);

         a=~a;

         printf(" The a‘s 1 complement(hexidecimal) is %x \n",a);

}

 

/*

 The a‘s 1 complement(decimal) is -235

 The a‘s 1 complement(hexidecimal) is ffffff15

Press any key to continue

*/

==============================================================

【程序56】

题目:画图,学用circle画圆形。   

1.程序分析:

2.程序源代码:

#include <stdio.h>

#include <graphics.h>

main(){

         int driver,mode,i;

         float j=1,k=1;

         driver=VGA;mode=VGAHI;

         initgraph(&driver,&mode,"");

         setbkcolor(YELLOW);

         for(i=0;i<=25;i++){

                   setcolor(8);

                   circle(310,250,k);

                   k=k+j;

                   j=j+0.3;

         }

}

==============================================================

【程序57】

题目:画图,学用line画直线。

1.程序分析:           

2.程序源代码:

#include "graphics.h"

main(){

         int driver,mode,i;

         float x0,y0,y1,x1;

         float j=12,k;

         driver=VGA;mode=VGAHI;

         initgraph(&driver,&mode,"");

         setbkcolor(GREEN);

         x0=263;y0=263;y1=275;x1=275;

         for(i=0;i<=18;i++){

                   setcolor(5);

                   line(x0,y0,x0,y1);

                   x0=x0-5;

                   y0=y0-5;

                   x1=x1+5;

                   y1=y1+5;

                   j=j+10;

         }

         x0=263;y1=275;y0=263;

         for(i=0;i<=20;i++){

                   setcolor(5);

                   line(x0,y0,x0,y1);

                   x0=x0+5;

                   y0=y0+5;

                   y1=y1-5;

         }

}

==============================================================

【程序58】

题目:画图,学用rectangle画方形。   

1.程序分析:利用for循环控制100-999个数,每个数分解出个位,十位,百位。

2.程序源代码:

#include "graphics.h"

main(){

         int x0,y0,y1,x1,driver,mode,i;

         driver=VGA;mode=VGAHI;

         initgraph(&driver,&mode,"");

         setbkcolor(YELLOW);

         x0=263;y0=263;y1=275;x1=275;

         for(i=0;i<=18;i++){

                   setcolor(1);

                   rectangle(x0,y0,x1,y1);

                   x0=x0-5;

                   y0=y0-5;

                   x1=x1+5;

                   y1=y1+5;

         }

         settextstyle(DEFAULT_FONT,HORIZ_DIR,2);

         outtextxy(150,40,"How beautiful it is!");

         line(130,60,480,60);

         setcolor(2);

         circle(269,269,137);

}

==============================================================

【程序59】

题目:画图,综合例子。

1.程序分析:

2.程序源代码:

#include<stdio.h>

#define PAI 3.1415926

#define B 0.809

#include <graphics.h>

#include <math.h>

main(){

         int i,j,k,x0,y0,x,y,driver,mode;

         float a;

         driver=CGA;mode=CGAC0;

         initgraph(&driver,&mode,"");

         setcolor(3);

         setbkcolor(GREEN);

         x0=150;y0=100;

         circle(x0,y0,10);

         circle(x0,y0,20);

         circle(x0,y0,50);

         for(i=0;i<16;i++){

         a=(2*PAI/16)*i;

         x=ceil(x0+48*cos(a));

         y=ceil(y0+48*sin(a)*B);

         setcolor(2); line(x0,y0,x,y);}

         setcolor(3);circle(x0,y0,60);

         /* Make 0 time normal size letters */

         settextstyle(DEFAULT_FONT,HORIZ_DIR,0);

         outtextxy(10,170,"press a key");

         getch();

         setfillstyle(HATCH_FILL,YELLOW);

         floodfill(202,100,WHITE);

         getch();

         for(k=0;k<=500;k++){

                   setcolor(3);

                   for(i=0;i<=16;i++){

                            a=(2*PAI/16)*i+(2*PAI/180)*k;

                            x=ceil(x0+48*cos(a));

                            y=ceil(y0+48+sin(a)*B);

                            setcolor(2); line(x0,y0,x,y);

                   }

                   for(j=1;j<=50;j++){

                            a=(2*PAI/16)*i+(2*PAI/180)*k-1;

                            x=ceil(x0+48*cos(a));

                            y=ceil(y0+48*sin(a)*B);

                            line(x0,y0,x,y);

                   }

         }

         restorecrtmode();

}

==============================================================

【程序60】

题目:画图,综合例子。   

1.程序分析:

2.程序源代码:

#include "stdio.h"

#include "graphics.h"

#define LEFT 0

#define TOP 0

#define RIGHT 639

#define BOTTOM 479

#define LINES 400

#define MAXCOLOR 15

main(){

         int driver,mode,error;

         int x1,y1;

         int x2,y2;

         int dx1,dy1,dx2,dy2,i=1;

         int count=0;

         int color=0;

         driver=VGA;

         mode=VGAHI;

         initgraph(&driver,&mode,"");

         x1=x2=y1=y2=10;

         dx1=dy1=2;

         dx2=dy2=3;

         while(!kbhit()){

                   line(x1,y1,x2,y2);

                   x1+=dx1;y1+=dy1;

                   x2+=dx2;y2+dy2;

                   if(x1<=LEFT||x1>=RIGHT)

                            dx1=-dx1;

                   if(y1<=TOP||y1>=BOTTOM)

                            dy1=-dy1;

                   if(x2<=LEFT||x2>=RIGHT)

                            dx2=-dx2;        

                   if(y2<=TOP||y2>=BOTTOM)

                            dy2=-dy2;

                   if(++count>LINES){

                            setcolor(color);

                            color=(color>=MAXCOLOR)?0:++color;

                   }

         }

         closegraph();

}

========================================================

【程序61】

题目:打印出杨辉三角形(要求打印出10行如下图)   

1.程序分析:

       1

      1  1

      1  2  1

      1  3  3  1

      1  4  6  4  1

      1  5  10 10 5  1 

2.程序源代码:

#include<stdio.h>

void main(){

         int i,j;

         int a[10][10];

         printf("\n");

         for(i=0;i<10;i++){

                   a[i][0]=1;

                   a[i][i]=1;

         }

         for(i=2;i<10;i++)

                   for(j=1;j<i;j++)

                            a[i][j]=a[i-1][j-1]+a[i-1][j];

         for(i=0;i<10;i++){

                   for(j=0;j<=i;j++)

                            printf("%5d",a[i][j]);

                   printf("\n");

         }

}

/*

    1

    1    1

    1    2    1

    1    3    3    1

    1    4    6    4    1

    1    5   10   10    5    1

    1    6   15   20   15    6    1

    1    7   21   35   35   21    7    1

    1    8   28   56   70   56   28    8    1

    1    9   36   84  126  126   84   36    9    1

Press any key to continue

*/

==============================================================

【程序62】

题目:学习putpixel画点。

1.程序分析:            

2.程序源代码:

#include "stdio.h"

#include "graphics.h"

main(){

         int i,j,driver=VGA,mode=VGAHI;

         initgraph(&driver,&mode,"");

         setbkcolor(YELLOW);

         for(i=50;i<=230;i+=20)

                   for(j=50;j<=230;j++)

                            putpixel(i,j,1);

         for(j=50;j<=230;j+=20)

                   for(i=50;i<=230;i++)

                            putpixel(i,j,1);

}

==============================================================

【程序63】

题目:画椭圆ellipse   

1.程序分析:

2.程序源代码:

#include "stdio.h"

#include "graphics.h"

#include "conio.h"

main(){

         int x=360,y=160,driver=VGA,mode=VGAHI;

         int num=20,i;

         int top,bottom;

         initgraph(&driver,&mode,"");

         top=y-30;

         bottom=y-30;

         for(i=0;i<num;i++){

                   ellipse(250,250,0,360,top,bottom);

                   top-=5;

                   bottom+=5;

         }

         getch();

}

==============================================================

【程序64】

题目:利用ellipse and rectangle 画图。

2.程序源代码:

#include "stdio.h"

#include "graphics.h"

#include "conio.h"

main(){

         int driver=VGA,mode=VGAHI;

         int i,num=15,top=50;

         int left=20,right=50;

         initgraph(&driver,&mode,"");

         for(i=0;i<num;i++){

                   ellipse(250,250,0,360,right,left);

                   ellipse(250,250,0,360,20,top);

                   rectangle(20-2*i,20-2*i,10*(i+2),10*(i+2));

                   right+=5;

                   left+=5;

                   top+=10;

         }

         getch();

}

==============================================================

【程序65】

题目:一个最优美的图案。   

1.程序分析:

2.程序源代码:

#include "graphics.h"

#include "math.h"

#include "dos.h"

#include "conio.h"

#include "stdlib.h"

#include "stdio.h"

#include "stdarg.h"

#define MAXPTS 15

#define PI 3.1415926

struct PTS {

         int x,y;

};

double AspectRatio=0.85;

void LineToDemo(void){

         struct viewporttype vp;

         struct PTS points[MAXPTS];

         int i, j, h, w, xcenter, ycenter;

         int radius, angle, step;

         double rads;

         printf(" MoveTo / LineTo Demonstration" );

         getviewsettings( &vp );

         h = vp.bottom - vp.top;

         w = vp.right - vp.left;

         xcenter = w / 2;                                      //Determine the center of circle

         ycenter = h / 2;

         radius = (h - 30) / (AspectRatio * 2);

         step = 360 / MAXPTS;                         // Determine # of increments

         angle = 0;                                                //Begin at zero degrees

         for( i=0 ; i<MAXPTS ; ++i ){     //Determine circle intercepts

                   rads = (double)angle * PI  //180.0; /* Convert angle to radians

                   points[i].x = xcenter + (int)( cos(rads) * radius );

                   points[i].y = ycenter - (int)( sin(rads) * radius * AspectRatio );

                   angle += step;                               // Move to next increment

         }

         circle( xcenter, ycenter, radius );                           // Draw bounding circle

         for( i=0 ; i<MAXPTS ; ++i ){                                 // Draw the cords to the circle

                   for( j=i ; j<MAXPTS ; ++j ){                        //For each remaining intersect

                            moveto(points[i].x, points[i].y);         // Move to beginning of cord

                            lineto(points[j].x, points[j].y);   //Draw the cord

                   }

         }

}

main(){

         int driver,mode;

         driver=CGA;mode=CGAC0;

         initgraph(&driver,&mode,"");

         setcolor(3);

         setbkcolor(GREEN);

         LineToDemo();

}

==============================================================

【程序66】

题目:输入3个数a,b,c,按大小顺序输出。   

1.程序分析:利用指针方法。

2.程序源代码:

#include<stdio.h>

swap(int *p1,int *p2){

         int p;

         p=*p1;

         *p1=*p2;

         *p2=p;

}

void main(){

         int n1,n2,n3;

         int *pointer1,*pointer2,*pointer3;

         printf("please input 3 number:n1,n2,n3:");

         scanf("%d %d %d",&n1,&n2,&n3);

         pointer1=&n1;

         pointer2=&n2;

         pointer3=&n3;

         if(n1>n2) swap(pointer1,pointer2);

         if(n1>n3) swap(pointer1,pointer3);

         if(n2>n3) swap(pointer2,pointer3);

         printf("the sorted numbers are:%d,%d,%d\n",n1,n2,n3);

}

/*

please input 3 number:n1,n2,n3:4 5 3

the sorted numbers are:3,4,5

Press any key to continue

*/

==============================================================

【程序67】

题目:输入数组,最大的与第一个元素交换,最小的与最后一个元素交换,输出数组。

1.程序分析:谭浩强的书中答案有问题。      

2.程序源代码:

#include<stdio.h>

input(int number[10]){

         int i;

         printf("Please input nine numbers: ");

         for(i=0;i<9;i++)

                   scanf("%d ",&number[i]);

         scanf("%d",&number[9]);

}

max_min(int array[10]){

         int *max,*min,k,l;

         int *p,*arr_end;

         arr_end=array+10;

         max=min=array;

         for(p=array+1;p<arr_end;p++)

                   if(*p>*max)

                            max=p;

                   else if(*p<*min)

                            min=p;

         k=*max;

         l=*min;

         *p=array[0];array[0]=l;l=*p;

         *p=array[9];array[9]=k;k=*p;

         return;

}

output(int array[10]){

         int *p;

         for(p=array;p<array+9;p++)

         printf("%d,",*p);

         printf("%d\n",array[9]);

}

void main(){

         int number[10];

         input(number);

         max_min(number);

         output(number);

}

==============================================================

【程序68】

题目:有n个整数,使其前面各数顺序向后移m个位置,最后m个数变成最前面的m个数

1.程序分析:

2.程序源代码:

#include<stdio.h>

move(int array[20],int n,int m){

         int *p,array_end;

         array_end=*(array+n-1);

         for(p=array+n-1;p>array;p--)

                   *p=*(p-1);

         *array=array_end;

         m--;

         if(m>0)

                   move(array,n,m);

}

void main(){

         int number[20],n,m,i;

         printf("the total numbers is:");

         scanf("%d",&n);

         printf("back m:");

         scanf("%d",&m);

         printf("Please input all the number: ");

         for(i=0;i<n-1;i++)

                   scanf("%d ",&number[i]);

         scanf("%d",&number[n-1]);

         move(number,n,m);

         for(i=0;i<n-1;i++)

                   printf("%d,",number[i]);

         printf("%d",number[n-1]);

         printf("\n");

}

/*

the total numbers is:5

back m:9

Please input all the number: 7 6 5 4 9

6,5,4,9,7

Press any key to continue

*/

==============================================================

【程序69】

题目:有n个人围成一圈,顺序排号。从第一个人开始报数(从1到3报数),凡报到3的人退出

   圈子,问最后留下的是原来第几号的那位。

1. 程序分析:

2.程序源代码:

#include<stdio.h>

#define nmax 50

void main(){

         int i,k,m,n,num[nmax],*p;

         printf("please input the total of numbers:");

         scanf("%d",&n);

         p=num;

         for(i=0;i<n;i++)

                   *(p+i)=i+1;

         i=0;

         k=0;

         m=0;

         while(m<n-1){

                   if(*(p+i)!=0)

                            k++;

                   if(k==3){

                            *(p+i)=0;

                            k=0;

                            m++;

                   }

                   i++;

                   if(i==n) i=0;

         }

         while(*p==0)

                   p++;

         printf("%d is left\n",*p);

}

/*

please input the total of numbers:5

4 is left

Press any key to continue

*/

==============================================================

【程序70】

题目:写一个函数,求一个字符串的长度,在main函数中输入字符串,并输出其长度。   

1.程序分析:

2.程序源代码:

#include<stdio.h>

#include<math.h>

length(char *p){

         int n;

         n=0;

         while(*p!=‘\0‘){

                   n++;

                   p++;

         }

         return n;

}

void main(){

         int len;

         char *str[20];

         printf("please input a string:\n");

         scanf("%s",str);

         len=length(*str);

         printf("the string has %d characters.",len);

}

==============================================================

【程序71】

题目:编写input()和output()函数输入,输出5个学生的数据记录。

1.程序分析:

2.程序源代码:

#include<stdio.h>

#define N 5

struct student{

         char num[6];

         char name[8];

         int score[4];

} stu[N];

input(struct student stu[]){

         int i,j;

         for(i=0;i<N;i++){

                   printf("\n please input %d of %d ",i+1,N);

                   printf("num: ");

                   scanf("%s",stu[i].num);

                   printf("name: ");

                   scanf("%s",stu[i].name);

                   for(j=0;j<3;j++){

                            printf("score %d: ",j+1);

                            scanf("%d",&stu[i].score[j]);

                   }

                   printf("\n");

         }

}

print(struct student stu[]){

         int i,j;

         printf("\nNo. Name Sco1 Sco2 Sco3\n");

         for(i=0;i<N;i++){

                   printf("%-6s%-10s",stu[i].num,stu[i].name);

                   for(j=0;j<3;j++)

                            printf("%-8d",stu[i].score[j]);

                   printf("\n");

         }

}

void main(){

         input(stu);

         print(stu);

}

==============================================================

【程序72】

题目:创建一个链表。

1.程序分析:           

2.程序源代码:

#include <stdlib.h>

#include<stdio.h>

struct list{

         int data;

         struct list *next;

};

typedef struct list node;

typedef node *link;

void main(){

         link ptr,head;

         int num,i;

         ptr=(link)malloc(sizeof(node));

         ptr=head;

         printf("please input 5 numbers==>\n");

         for(i=0;i<=4;i++){

                   scanf("%d",&num);

                   ptr->data=num;

                   ptr->next=(link)malloc(sizeof(node));

                   if(i==4) ptr->next=NULL;

                   else ptr=ptr->next;

         }

         ptr=head;

         while(ptr!=NULL){

                   printf("The value is ==>%d\n",ptr->data);

                   ptr=ptr->next;

         }

}

==============================================================

【程序73】

题目:反向输出一个链表。   

1.程序分析:

2.程序源代码:

/*reverse output a list*/

#include "stdlib.h"

#include "stdio.h"

struct list{

         int data;

         struct list *next;

};

typedef struct list node;

typedef node *link;

void main(){

         link ptr,head,tail;

         int num,i;

         tail=(link)malloc(sizeof(node));

         tail->next=NULL;

         ptr=tail;

         printf("\nplease input 5 data==>\n");

         for(i=0;i<=4;i++){

                   scanf("%d",&num);

                   ptr->data=num;

                   head=(link)malloc(sizeof(node));

                   head->next=ptr;

                   ptr=head;

         }

         ptr=ptr->next;

         while(ptr!=NULL){

                   printf("The value is ==>%d\n",ptr->data);

                   ptr=ptr->next;

         }

}

/*

please input 5 data==>

43213

544

7

87

5

The value is ==>5

The value is ==>87

The value is ==>7

The value is ==>544

The value is ==>43213

Press any key to continue

*/

==============================================================

【程序74】

题目:连接两个链表。

1.程序分析:

2.程序源代码:

#include "stdlib.h"

#include "stdio.h"

struct list{

         int data;

         struct list *next;

};

typedef struct list node;

typedef node *link;

link delete_node(link pointer,link tmp){

         if (tmp==NULL)                                             //delete first node

                   return pointer->next;

         else{

                   if(tmp->next->next==NULL)    //delete last node

                            tmp->next=NULL;

                   else                                                 //delete the other node

                            tmp->next=tmp->next->next;

                   return pointer;

         }

}

void selection_sort(link pointer,int num){

         link tmp,btmp;

         int i,min;

         for(i=0;i<num;i++){

                   tmp=pointer;

                   min=tmp->data;

                   btmp=NULL;

                   while(tmp->next){

                            if(min>tmp->next->data){

                                     min=tmp->next->data;

                                     btmp=tmp;

                            }

                            tmp=tmp->next;

                   }

                   printf(" %d\n",min);

                   pointer=delete_node(pointer,btmp);

         }

}

link create_list(int array[],int num){

         link tmp1,tmp2,pointer;

         int i;

         pointer=(link)malloc(sizeof(node));

         pointer->data=array[0];

         tmp1=pointer;

         for(i=1;i<num;i++){

                   tmp2=(link)malloc(sizeof(node));

                   tmp2->next=NULL;

                   tmp2->data=array[i];

                   tmp1->next=tmp2;

                   tmp1=tmp1->next;

         }

         return pointer;

}

link concatenate(link pointer1,link pointer2){

         link tmp;

         tmp=pointer1;

         while(tmp->next)

         tmp=tmp->next;

         tmp->next=pointer2;

         return pointer1;

}

void main(void){

         int arr1[]={3,12,8,9,11};

         link ptr;

         ptr=create_list(arr1,5);

         selection_sort(ptr,5);

}

==============================================================

【程序75】

题目:放松一下,算一道简单的题目。

1.程序分析:

2.程序源代码:

#include<stdio.h>

void main(){

int i,n;

for(i=1;i<5;i++){

         n=0;

         if(i!=1)

                   n=n+1;

         if(i==3)

                   n=n+1;

         if(i==4)

                   n=n+1;

         if(i!=4)

                   n=n+1;

         if(n==3)

                   printf("zhu hao shi de shi:%c\n",64+i);

         }

}

/*

zhu hao shi de shi:C

Press any key to continue

*/

==============================================================

【程序76】

题目:编写一个函数,输入n为偶数时,调用函数求1/2+1/4+...+1/n,当输入n为奇数时,调用函数

   1/1+1/3+...+1/n(利用指针函数)

1.程序分析:

2.程序源代码:

#include "stdio.h"

float peven(int n){

         float s;

         int i;

         s=1;

         for(i=2;i<=n;i+=2)

                   s+=1/(float)i;

         return(s);

}

float podd(int n){

         float s;

         int i;

         s=0;

         for(i=1;i<=n;i+=2)

                   s+=1/(float)i;

         return(s);

}

float dcall(float (*fp)(int n),int n){

         float s;

         s=(fp)(n);

         return(s);

}

void main(){

         //float peven(),podd(),dcall();

         float sum;

         int n;

         printf("Please input a number: ");

         while (1){

                   scanf("%d",&n);

                   if(n>1)

                            break;

         }

         if(n%2==0){

                   printf("Even=");

                   sum=dcall(peven,n);

         }

         else{

                   printf("Odd=");

                   sum=dcall(podd,n);

         }

         printf("%f\n",sum);

}

/*

Please input a number: 66

Even=3.044399

Press any key to continue

*/

==============================================================

【程序77】

题目:填空练习(指向指针的指针)

1.程序分析:     

2.程序源代码:

#include<stdio.h>

void main(){

         char *s[]={"man","woman","girl","boy","sister"};

         char **q;

         int k;

         for(k=0;k<5;k++){

                   /*这里填写什么语句?*/

                   printf("%s\n",*q);

         }

}

==============================================================

【程序78】

题目:找到年龄最大的人,并输出。请找出程序中有什么问题。

1.程序分析:

2.程序源代码:

#include "stdio.h"

#define N 4

static struct man{

         char name[20];

         int age;

} person[N]={"li",18,"wang",19,"zhang",20,"sun",22};

main(){

         struct man *q,*p;

         int i,m=0;

         p=person;

         for (i=0;i<N;i++){

                   if(m<p->age)

                            q=p++;

                            m=q->age;

         }

         printf("%s,%d",(*q).name,(*q).age);

}

==============================================================

【程序79】

题目:字符串排序。

1.程序分析:

2.程序源代码:

#include<stdio.h>

void main(){

         char *str1[20],*str2[20],*str3[20];

         char swap();

         printf("please input three strings\n");

         scanf("%s",str1);

         scanf("%s",str2);

         scanf("%s",str3);

         if(strcmp(str1,str2)>0) swap(str1,str2);

         if(strcmp(str1,str3)>0) swap(str1,str3);

         if(strcmp(str2,str3)>0) swap(str2,str3);

         printf("after being sorted\n");

         printf("%s\n%s\n%s\n",str1,str2,str3);

}

char swap(char *p1,char *p2){

         char *p[20];

         strcpy(p,p1);

         strcpy(p1,p2);

         strcpy(p2,p);

}

==============================================================

【程序80】

题目:海滩上有一堆桃子,五只猴子来分。第一只猴子把这堆桃子凭据分为五份,多了一个,这只

   猴子把多的一个扔入海中,拿走了一份。第二只猴子把剩下的桃子又平均分成五份,又多了

   一个,它同样把多的一个扔入海中,拿走了一份,第三、第四、第五只猴子都是这样做的,

   问海滩上原来最少有多少个桃子?

1.程序分析:

2.程序源代码:

#include<stdio.h>

void main(){

         int i,m,j,k,count;

         for(i=4;i<10000;i+=4){

                   count=0;

                   m=i;

                   for(k=0;k<5;k++){

                            j=i/4*5+1;

                            i=j;

                            if(j%4==0)

                                     count++;

                            else

                                     break;

                   }

                   i=m;

                   if(count==4){

                            printf("%d\n",i);

                            break;

                   }

         }

}

/*

Please input a number: 66

Even=3.044399

Press any key to continue

*/

==============================================================

【程序81】

题目:809*??=800*??+9*??+1 其中??代表的两位数,8*??的结果为两位数,9*??的结果为3位数。求??代表的两位数,及809*??后的结果。

1.程序分析:

2.程序源代码:

#include<stdio.h>

output(long b,long i){

         printf("%ld/%ld=809*%ld+%ld\n",b,i,i,b%i);

}

void main(){

         long int a,b,i;

         a=809;

         for(i=10;i<100;i++){

                   b=i*a+1;

                   if(b>=1000&&b<=10000&&8*i<100&&9*i>=100)

                            output(b,i);

         }

}

/*

9709/12=809*12+1

Press any key to continue

*/

==============================================================

【程序82】

题目:八进制转换为十进制

1.程序分析:           

2.程序源代码:

#include<stdio.h>

void main(){

         char *p,s[6];

         int n;

         p=s;

         printf("Please input a character: ");

         gets(p);

         n=0;

         while(*(p)!=‘\0‘){

                   n=n*8+*p-‘0‘;

                   p++;

         }

         printf("after is: %d\n",n);

}

/*

Please input a character: a

after is: 49

Press any key to continue

*/

==============================================================

【程序83】

题目:求0—7所能组成的奇数个数。

1.程序分析:

2.程序源代码:

#include<stdio.h>

void main(){

         long sum=4,s=4;

         int j;

         for(j=2;j<=8;j++){ //j is place of number

                   printf(" The number is: %ld",sum);

                   if(j<=2)

                            s*=7;

                   else

                            s*=8;

                   sum+=s;

         }

         printf("\nsum=%ld",sum);

}

/*

The number is: 4

The number is: 32

The number is: 256

The number is: 2048

The number is: 16384

The number is: 131072

The number is: 1048576

sum=8388608Press any key to continue

*/

==============================================================

【程序84】

题目:一个偶数总能表示为两个素数之和。

1.程序分析:

2.程序源代码:

#include<stdio.h>

#include <math.h>

void main(){

         int a,b,c,d;

         printf("Please input an even number: ");

         scanf("%d",&a);

         for(b=3;b<=a/2;b+=2){

                   for(c=2;c<=sqrt(b);c++)

                            if(b%c==0)

                                     break;

                   if(c>sqrt(b))

                            d=a-b;

                   else

                            break;

                   for(c=2;c<=sqrt(d);c++)

                            if(d%c==0)

                                     break;

                   if(c>sqrt(d))

                            printf("%d=%d+%d\n",a,b,d);

         }

}

/*

Please input an even number: 34

34=3+31

34=5+29

Press any key to continue

*/

==============================================================

【程序85】

题目:判断一个素数能被几个9整除

1.程序分析:

2.程序源代码:

#include<stdio.h>

void main(){

         long int m9=9,sum=9;

         int zi,n1=1,c9=1;

         printf("Please input a prim number: ");

         scanf("%d",&zi);

         while(n1!=0){

                   if(!(sum%zi))

                            n1=0;

                   else{

                            m9=m9*10;

                            sum=sum+m9;

                            c9++;

                   }

         }

         printf("%ld,can be divided by %d \"9\"\n",sum,c9);

}

/*

Please input a prim number: 17

-727379969,can be divided by 12 "9"

Press any key to continue

*/

==============================================================

【程序86】

题目:两个字符串连接程序

1.程序分析:

2.程序源代码:

#include<stdio.h>

void main(){

         char a[]="acegikm";

         char b[]="bdfhjlnpq";

         char c[80],*p;

         int i=0,j=0,k=0;

         while(a[i]!=‘\0‘&&b[j]!=‘\0‘){

                   if (a[i]<b[j]) {

                            c[k]=a[i];

                            i++;

                   }

                   else

                            c[k]=b[j++];

                   k++;

         }

         c[k]=‘\0‘;

         if(a[i]==‘\0‘)

                   p=b+j;

         else

                   p=a+i;

         strcat(c,p);

         puts(c);

}

==============================================================

【程序87】

题目:回答结果(结构体变量传递)

1.程序分析:     

2.程序源代码:

#include<stdio.h>

struct student{

         int x;

         char c;

} a;

f(struct student b){

         b.x=20;

         b.c=‘y‘;

}

void main(){

         a.x=3;

         a.c=‘a‘;

         f(a);

         printf("%d,%c\n",a.x,a.c);

}

/*

3,a

Press any key to continue

*/

==============================================================

【程序88】

题目:读取7个数(1—50)的整数值,每读取一个值,程序打印出该值个数的*。

1.程序分析:

2.程序源代码:

#include<stdio.h>

void main(){

         int i,a,n=1;

         while(n<=7){

                   do {

                            scanf("%d",&a);

                   }while(a<1||a>50);

                   for(i=1;i<=a;i++)

                            printf("*");

                   printf("\n");

                   n++;

         }

         getchar();

}

 

/*

3

***

4

****

5

*****

6

******

7

*******

8

********

9

*********

Press any key to continue

*/

==============================================================

【程序89】

题目:某个公司采用公用电话传递数据,数据是四位的整数,在传递过程中是加密的,加密规则如下:

   每位数字都加上5,然后用和除以10的余数代替该数字,再将第一位和第四位交换,第二位和第三位交换。

1.程序分析:

2.程序源代码:

#include<stdio.h>

void main(){

         int a,i,aa[4],t;

         printf("Please input the data(4): ");

         scanf("%d",&a);

         aa[0]=a%10;

         aa[1]=a%100/10;

         aa[2]=a%1000/100;

         aa[3]=a/1000;

         for(i=0;i<=3;i++){

                   aa[i]+=5;

                   aa[i]%=10;

         }

         for(i=0;i<=3/2;i++){

                   t=aa[i];

                   aa[i]=aa[3-i];

                   aa[3-i]=t;

         }

         printf("the encryted data is: ");

         for(i=3;i>=0;i--)

                   printf("%d",aa[i]);

         printf("\n");

}

/*

Please input the data(4): 5467

the encryted data is: 2190

Press any key to continue

*/

==============================================================

【程序90】

题目:专升本一题,读结果。

1.程序分析:

2.程序源代码:

#include <stdio.h>

#define M 5

void main(){

         int a[M]={1,2,3,4,5};

         int i=0,j=M-1,t;

         while(i<j) {

                   t=*(a+i);

                   *(a+i)=*(a+j);

                   *(a+j)=t;

                   i++;

                   j--;

         }

         for(i=0;i<M;i++){

                   printf("%d ",*(a+i));

         }

         printf("\n");

}

/*

5 4 3 2 1

Press any key to continue

*/

==============================================================

【程序91】

题目:时间函数举例1

1.程序分析:

2.程序源代码:

#include "stdio.h"

#include "time.h"

void main(){

         time_t lt;                     /define a longint time varible

         lt=time(NULL);                            //system time and date

         printf(ctime(<));                           //english format output

         printf(asctime(localtime(<)));    //tranfer to tm

         printf(asctime(gmtime(<)));       //tranfer to Greenwich time

}

==============================================================

【程序92】

题目:时间函数举例2

1.程序分析:           

2.程序源代码:

/*calculate time*/

#include "time.h"

#include "stdio.h"

void main(){

         time_t start,end;

         int i;

         start=time(NULL);

         for(i=0;i<3000;i++){

                   printf("\1\1\1\1\1\1\1\1\1\1\n");

         }

         end=time(NULL);

         printf("\1: The different is %6.3f\n",difftime(end,start));

}

==============================================================

【程序93】

题目:时间函数举例3

1.程序分析:

2.程序源代码:

/*calculate time*/

#include "time.h"

#include "stdio.h"

main(){

         clock_t start,end;

         int i;

         double var;

         start=clock();

         for(i=0;i<10000;i++){

                   printf("\1\1\1\1\1\1\1\1\1\1\n");

         }

         end=clock();

         printf("\1: The different is %6.3f\n",(double)(end-start));

}

==============================================================

【程序94】

题目:时间函数举例4,一个猜数游戏,判断一个人反应快慢。(版主初学时编的)

1.程序分析:

2.程序源代码:

#include "stdio.h"

#include "time.h"

#include "stdlib.h"

void main(){

         char c;

         clock_t start,end;

         time_t a,b;

         double var;

         int i,guess;

         srand(time(NULL));

         printf("do you want to play it.(‘y‘ or ‘n‘) \n");

         loop:

         while((c=getchar())==‘y‘){

                   i=rand()%100;

                   printf("\nplease input number you guess:\n");

                   start=clock();

                   a=time(NULL);

                   scanf("%d",&guess);

                   while(guess!=i){

                            if(guess>i){

                                     printf("please input a little smaller.\n");

                                     scanf("%d",&guess);

                            }

                            else{

                                     printf("please input a little bigger.\n");

                                     scanf("%d",&guess);

                            }

                   }

                   end=clock();

                   b=time(NULL);

                   printf("\1: It took you %6.3f seconds\n",var=(double)(end-start)/18.2);

                   printf("\1: it took you %6.3f seconds\n\n",difftime(b,a));

                   if(var<15)

                            printf("\1\1 You are very clever! \1\1\n\n");

                   else if(var<25)

                            printf("\1\1 you are normal! \1\1\n\n");

                   else

                            printf("\1\1 you are stupid! \1\1\n\n");

                   printf("\1\1 Congradulations \1\1\n\n");

                   printf("The number you guess is %d",i);

         }

         printf("\ndo you want to try it again?(\"yy\".or.\"n\")\n");

         if((c=getchar())==‘y‘)

                   goto loop;

}

==============================================================

【程序95】

题目:家庭财务管理小程序

1.程序分析:

2.程序源代码:

/*money management system*/

#include <stdio.h>

#include <dos.h>

void main(){

         FILE *fp;

         struct date d;

         float sum,chm=0.0;

         int len,i,j=0;

         int c;

         char ch[4]="",ch1[16]="",chtime[12]="",chshop[16],chmoney[8];

         pp: clrscr();

         sum=0.0;

         gotoxy(1,1);printf("|---------------------------------------------------------------------------|");

         gotoxy(1,2);printf("| money management system(C1.0) 2000.03 |");

         gotoxy(1,3);printf("|---------------------------------------------------------------------------|");

         gotoxy(1,4);printf("| -- money records -- | -- today cost list -- |");

         gotoxy(1,5);printf("| ------------------------ |-------------------------------------|");

         gotoxy(1,6);printf("| date: -------------- | |");

         gotoxy(1,7);printf("| | | | |");

         gotoxy(1,8);printf("| -------------- | |");

         gotoxy(1,9);printf("| thgs: ------------------ | |");

         gotoxy(1,10);printf("| | | | |");

         gotoxy(1,11);printf("| ------------------ | |");

         gotoxy(1,12);printf("| cost: ---------- | |");

         gotoxy(1,13);printf("| | | | |");

         gotoxy(1,14);printf("| ---------- | |");

         gotoxy(1,15);printf("| | |");

         gotoxy(1,16);printf("| | |");

         gotoxy(1,17);printf("| | |");

         gotoxy(1,18);printf("| | |");

         gotoxy(1,19);printf("| | |");

         gotoxy(1,20);printf("| | |");

         gotoxy(1,21);printf("| | |");

         gotoxy(1,22);printf("| | |");

         gotoxy(1,23);printf("|---------------------------------------------------------------------------|");

         i=0;

         getdate(&d);

         sprintf(chtime,"%4d.%02d.%02d",d.da_year,d.da_mon,d.da_day);

         for(;;){

                   gotoxy(3,24);printf(" Tab __browse cost list Esc __quit");

                   gotoxy(13,10);printf(" ");

                   gotoxy(13,13);printf(" ");

                   gotoxy(13,7);printf("%s",chtime);

                   j=18;

                   ch[0]=getchar();

                   if(ch[0]==27)

                            break;

                   strcpy(chshop,"");

                   strcpy(chmoney,"");

                   if(ch[0]==9){

                            mm:i=0;

                            fp=fopen("home.dat","r+");

                            gotoxy(3,24);printf(" ");

                            gotoxy(6,4);printf(" list records ");

                            gotoxy(1,5);printf("|-------------------------------------|");

                            gotoxy(41,4);printf(" ");

                            gotoxy(41,5);printf(" |");

                            while(fscanf(fp,"%10s%14s%f\n",chtime,chshop,&chm)!=EOF){

                                     if(i==36){

                                               getchar();

                                               i=0;

                                     }

                                     if ((i%36)<17){

                                               gotoxy(4,6+i);

                                               printf(" ");

                                               gotoxy(4,6+i);

                                     }

                                     else if((i%36)>16){

                                               gotoxy(41,4+i-17);

                                               printf(" ");

                                               gotoxy(42,4+i-17);

                                     }

                                     i++;

                                     sum=sum+chm;

                                     printf("%10s %-14s %6.1f\n",chtime,chshop,chm);

                            }

                            gotoxy(1,23);printf("|---------------------------------------------------------------------------|");

                            gotoxy(1,24);printf("| |");

                            gotoxy(1,25);printf("|---------------------------------------------------------------------------|");

                            gotoxy(10,24);printf("total is %8.1f$",sum);

                            fclose(fp);

                            gotoxy(49,24);printf("press any key to.....");getch();goto pp;

                   }

                   else{

                            while(ch[0]!=‘\r‘){

                                     if(j<10){

                                               strncat(chtime,ch,1);

                                               j++;

                                     }

                                     if(ch[0]==8){

                                               len=strlen(chtime)-1;

                                               if(j>15){

                                                        len=len+1;

                                                        j=11;

                                               }

                                               strcpy(ch1,"");

                                               j=j-2;

                                               strncat(ch1,chtime,len);

                                               strcpy(chtime,"");

                                               strncat(chtime,ch1,len-1);

                                               gotoxy(13,7);printf(" ");

                                     }

                                     gotoxy(13,7);printf("%s",chtime);ch[0]=getch();

                                     if(ch[0]==9)

                                     goto mm;

                                     if(ch[0]==27)

                                     exit(1);

                            }

                            gotoxy(3,24);printf(" ");

                            gotoxy(13,10);

                            j=0;

                            ch[0]=getch();

                            while(ch[0]!=‘\r‘){

                                     if (j<14){

                                               strncat(chshop,ch,1);

                                               j++;

                                     }

                                     if(ch[0]==8){

                                               len=strlen(chshop)-1;

                                               strcpy(ch1,"");

                                               j=j-2;

                                               strncat(ch1,chshop,len);

                                               strcpy(chshop,"");

                                               strncat(chshop,ch1,len-1);

                                               gotoxy(13,10);printf(" ");

                                     }

                                     gotoxy(13,10);

                                     printf("%s",chshop);

                                     ch[0]=getch();

                            }

                            gotoxy(13,13);

                            j=0;

                            ch[0]=getch();

                            while(ch[0]!=‘\r‘){

                                     if (j<6){

                                               strncat(chmoney,ch,1);

                                               j++;

                                     }

                                     if(ch[0]==8){

                                               len=strlen(chmoney)-1;

                                               strcpy(ch1,"");

                                              j=j-2;

                                               strncat(ch1,chmoney,len);

                                               strcpy(chmoney,"");

                                               strncat(chmoney,ch1,len-1);

                                               gotoxy(13,13);printf(" ");

                                     }

                                     gotoxy(13,13);printf("%s",chmoney);ch[0]=getch();

                            }

                            if((strlen(chshop)==0)||(strlen(chmoney)==0))

                                     continue;

                            if((fp=fopen("home.dat","a+"))!=NULL);

                            fprintf(fp,"%10s%14s%6s",chtime,chshop,chmoney);

                            fputc(‘\n‘,fp);

                            fclose(fp);

                            i++;

                            gotoxy(41,5+i);

                            printf("%10s %-14s %-6s",chtime,chshop,chmoney);

                   }

         }

}  

==============================================================

【程序96】

题目:计算字符串中子串出现的次数

1.程序分析:

2.程序源代码:

#include "string.h"

#include "stdio.h"

void main(){

         char str1[20],str2[20],*p1,*p2;

         int sum=0;

         printf("please input two strings\n");

         scanf("%s%s",str1,str2);

         p1=str1;

         p2=str2;

         while(*p1!=‘\0‘){

                   if(*p1==*p2){

                            while(*p1==*p2&&*p2!=‘\0‘){

                                     p1++;

                                     p2++;

                            }

                   }

                   else

                            p1++;

                   if(*p2==‘\0‘)

                            sum++;

                   p2=str2;

         }

         printf("all is : %d\n",sum);

         getchar();

}

==============================================================

【程序97】

题目:从键盘输入一些字符,逐个把它们送到磁盘上去,直到输入一个#为止。

1.程序分析:     

2.程序源代码:

#include "stdio.h"

void main(){

         FILE *fp;

         char ch,filename[10];

         scanf("%s",filename);

         if((fp=fopen(filename,"w"))==NULL){

                   printf("cannot open file\n");

                   exit(0);

         }

         ch=getchar();

         ch=getchar();

         while(ch!=‘#‘){

                   fputc(ch,fp);putchar(ch);

                   ch=getchar();

         }

         fclose(fp);

}

==============================================================

【程序98】

题目:从键盘输入一个字符串,将小写字母全部转换成大写字母,然后输出到一个磁盘文件“test”中保存。

   输入的字符串以!结束。

1.程序分析:

2.程序源代码:

#include "stdio.h"

void main(){

         FILE *fp;

         char str[100],filename[10];

         int i=0;

         if((fp=fopen("test","w"))==NULL){

                   printf("cannot open the file\n");

                   exit(0);

         }

         printf("please input a string:\n");

         gets(str);

         while(str[i]!=‘!‘){

                   if(str[i]>=‘a‘&&str[i]<=‘z‘)

                            str[i]=str[i]-32;

                   fputc(str[i],fp);

                   i++;

         }

         fclose(fp);

         fp=fopen("test","r");

         fgets(str,strlen(str)+1,fp);

         printf("%s\n",str);

         fclose(fp);

}

==============================================================

【程序99】

题目:有两个磁盘文件A和B,各存放一行字母,要求把这两个文件中的信息合并(按字母顺序排列),

   输出到一个新文件C中。

1.程序分析:

2.程序源代码:

#include "stdio.h"

void main(){

         FILE *fp;

         int i,j,n,ni;

         char c[160],t,ch;

         if((fp=fopen("A","r"))==NULL){

                   printf("file A cannot be opened\n");

                   exit(0);

         }

         printf("\n A contents are :\n");

         for(i=0;(ch=fgetc(fp))!=EOF;i++){

                   c[i]=ch;

                   putchar(c[i]);

         }

         fclose(fp);

         ni=i;

         if((fp=fopen("B","r"))==NULL){

                   printf("file B cannot be opened\n");

                   exit(0);

         }

         printf("\n B contents are :\n");

         for(i=0;(ch=fgetc(fp))!=EOF;i++){

                   c[i]=ch;

                   putchar(c[i]);

         }

         fclose(fp);

         n=i;

         for(i=0;i<n;i++)

         for(j=i+1;j<n;j++)

         if(c[i]>c[j]){

                   t=c[i];

                   c[i]=c[j];

                   c[j]=t;

         }

         printf("\n C file is:\n");

         fp=fopen("C","w");

         for(i=0;i<n;i++){

                   putc(c[i],fp);

                   putchar(c[i]);

         }

         fclose(fp);

}

==============================================================

【程序100】

题目:有五个学生,每个学生有3门课的成绩,从键盘输入以上数据(包括学生号,姓名,三门课成绩),计算出

   平均成绩,况原有的数据和计算出的平均分数存放在磁盘文件"stud"中。

1.程序分析:

2.程序源代码:

#include "stdio.h"

struct student{

         char num[6];

         char name[8];

         int score[3];

         float avr;

} stu[5];

main(){

         int i,j,sum;

         FILE *fp;

         /*input*/

         for(i=0;i<5;i++){

                   printf("\n please input No. %d score:\n",i);

                   printf("stuNo:");

                   scanf("%s",stu[i].num);

                   printf("name:");

                   scanf("%s",stu[i].name);

                   sum=0;

                   for(j=0;j<3;j++){

                            printf("score %d.",j+1);

                            scanf("%d",&stu[i].score[j]);

                            sum+=stu[i].score[j];

                   }

                   stu[i].avr=sum/3.0;

         }

         fp=fopen("stud","w");

         for(i=0;i<5;i++)

         if(fwrite(&stu[i],sizeof(struct student),1,fp)!=1)

                   printf("file write error\n");

         fclose(fp);

}

C语言经典程序100例

标签:字符串   form   etc   一个人   string   就会   extern   功能   this   

原文地址:https://www.cnblogs.com/zili/p/9739555.html

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