实验 2 C语言中的表达式及输入输出函数编程应用

#define _CRT_SECURE_NO_DEPRECATE

#include <stdio.h>
int main()
{
    int num;

    scanf("%d", &num);
    printf("2049%04d\n", num);

    scanf("%d", &num);
    printf("2049%04d\n", num);

    scanf("%d", &num);
    printf("2049%04d\n", num);

    return 0;
}

#define _CRT_SECURE_NO_DEPRECATE

#include<stdio.h>
int main()
{
    int num,i;

    for (i=1;i<=3;i++)
    {
        scanf("%d", &num);
        printf("2049%04d\n", num);
    }
    return 0;
}
%04d:右对齐，左边填充0，当输入变量宽度大于4时则输出变量的所有数字。

#include <stdio.h>
 int main() 
{ 
    int x=1234;
    float f=123.456; 
    double m=123.456; 
    char ch=‘a‘; 
    char a[]="Hello, world!"; 
    int y=3, z=4; 

    printf("%d %d\n", y, z); 
    printf("y=%d, z=%d\n", y,z); 
    printf("%8d,%2d\n", x,x);
    printf("%f, %8f, %8.1f, %0.2f, %.2e\n",f,f,f,f,f);
    printf("%lf\n",m); printf("%3c\n", ch);             
    printf("%s\n%15s\n%10.5s\n%2.5s\n%.3s\n",a,a,a,a,a); 

    return 0; 
}

#define _CRT_SECURE_NO_DEPRECATE

#include <stdio.h> 
int main()
{
    double x, y;
    char c1, c2, c3;
    int a1, a2, a3;

    scanf("%d%d%d", &a1, &a2, &a3);
    printf("%d,%d,%d\n", a1, a2, a3);

    scanf("%c%c%c", &c1, &c2, &c3);
    printf("%c%c%c\n", c1, c2, c3);

    scanf("%lf,%lf", &x, &y);
    printf("%lf,%lf\n", x, y);

    return 0;
}

#include<stdio.h>
int main()
{
    char ans1, ans2;

    printf("复习了没?(输入y或Y表示复习了，输入n或N表示没复习):");

    ans1 = getchar();
    getchar();

    printf("\n动手敲代码了没?(输入y或Y表示敲了，输入n或N表示木有敲):");

    ans2 = getchar();

    if (ans1 == ‘y‘ && ans2 == ‘y‘ || ans1 == ‘y‘ && ans2 == ‘Y‘ || ans1 == ‘Y‘ && ans2 == ‘y‘ || ans1 == ‘Y‘ && ans2 == ‘Y‘)
        printf("\n罗马不是一天建成的:)\n");
    else
        printf("\n罗马不是一天毁灭的。。。\n");
    return 0;
}

#include<stdio.h>
int main()
{
    char x;
    x = getchar();
    if (x >= ‘0‘ && x <= ‘9‘)
        printf("%c是数字字符\n", x);
    else if (x >= ‘a‘ && x <= ‘z‘ || x >= ‘A‘ && x <= ‘Z‘)
        printf("%c是英文字母\n", x);
    else
        printf("%c是其它字符\n", x);
    return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
    int sum = 1, x, i;
    char n;
    n = getchar();
    for (i = 1; i <= n; i++)
    {
        x = pow(2, i);
        sum = sum + x;
    }
    printf("n = %d 时,sum = %d\n",n, sum);
    return 0;
}