第五章、图的遍历

 1 #include <stdio.h>
 2 int book[101],sum,n,e[101][101];
 3 
 4 void dfs(int cur)
 5 {
 6   int i;
 7   printf("%d ",cur);
 8   sum++;
 9   if(sum==n) return;
10   for(i=1;i<=n;i++)
11   {
12     if(e[cur][i]==1 && book[i]==0)
13     {
14       book[i]=1;
15       dfs(i);
16     }
17   }
18   return;
19 }
20 
21 int main()
22 {
23   int i,j,m,a,b;
24   scanf("%d %d", &n, &m);
25                      
26   for(i = 1; i <= n; i++)
27     for(j = 1; j <= n; j++)
28       if(i==j) e[i][j]=0;
29         else e[i][j]=99999999;
30           
31   for(i=1;i<=m;i++)
32   {
33      scanf("%d %d", &a, &b);
34      e[a][b]=1;
35      e[b][a]=1;
36   }
37  
38   book[1]=1;
39   dfs(1);
40   getchar(); getchar();
41   return 0;
42 }
43 
44 /*
45 
46 5 5
47 1 2
48 1 3
49 1 5
50 2 4
51 3 5
52 
53 */

 1 #include <stdio.h>
 2 int book[101],n,e[101][101];
 3 
 4 void dfs(int cur)
 5 {
 6   int i;
 7   printf("%d ",cur);
 8   for(i=1;i<=n;i++)
 9   {
10     if(e[cur][i]==1 && book[i]==0)
11     {
12       book[i]=1;
13       dfs(i);
14     }
15   }
16   return;
17 }
18 
19 int main()
20 {
21   int i,j,m,a,b;
22   scanf("%d %d", &n, &m);
23                      
24   for(i = 1; i <= n; i++)
25     for(j = 1; j <= n; j++)
26       if(i==j) e[i][j]=0;
27         else e[i][j]=99999999;
28           
29   for(i=1;i<=m;i++)
30   {
31      scanf("%d %d", &a, &b);
32      e[a][b]=1;
33      e[b][a]=1;
34   }
35  
36   book[1]=1;
37   dfs(1);
38   getchar(); getchar();
39   return 0;
40 }
41 
42 /*
43 这组数据，使顶点四不连通
44 
45 5 5
46 1 2
47 1 3
48 1 5
49 2 3
50 3 5
51 
52 5 5
53 1 2
54 1 3
55 1 5
56 2 4
57 3 5
58 
59 */

 1 #include <stdio.h>
 2 int main()
 3 {
 4   int i,j,n,m,a,b,cur,book[101]={0},e[101][101];
 5   int que[10001],head,tail;
 6   scanf("%d %d", &n, &m);
 7   
 8   for(i = 1; i <= n; i++)
 9     for(j = 1; j <= n; j++)
10       if(i==j) e[i][j]=0;
11         else e[i][j]=99999999;
12           
13   for(i=1;i<=m;i++)
14   {
15      scanf("%d %d", &a, &b);
16      e[a][b]=1;
17      e[b][a]=1;
18   }  
19   
20   head=1;
21   tail=1;
22   
23   que[tail]=1;
24   tail++;
25   book[1]=1;
26   
27   while(head<tail)
28   {
29     cur=que[head];
30     for(i=1;i<=n;i++)
31     {
32       if(e[cur][i]==1 && book[i]==0)
33       {
34         que[tail]=i;
35         tail++;
36         book[i]=1;
37       }
38       if(tail>n) break;
39     }
40     head++;
41   }
42   
43   for(i=1;i<tail;i++)
44     printf("%d ",que[i]);
45 
46   getchar(); getchar();
47   return 0;
48 }
49 
50 /*
51 
52 5 5
53 1 2
54 1 3
55 1 5
56 2 4
57 3 5
58 
59 */

 1 #include <stdio.h>
 2 int min=99999999, book[101], n, e[101][101];
 3 
 4 void dfs(int cur, int dis)
 5 {
 6   int i;
 7   if(dis>min) return;
 8   if(cur==n)
 9   {
10     if(dis<min) min=dis;
11     return;
12   }
13 
14   for(i=1;i<=n;i++)
15   {
16     if(e[cur][i] !=99999999 && book[i]==0)
17     {
18       book[i]=1;
19       dfs(i,dis+e[cur][i]);
20       book[i]=0;
21     }
22   }
23   return;
24 }
25 
26 int main()
27 {
28   int i,j,m,a,b,c;
29   scanf("%d %d", &n, &m);
30                      
31   for(i = 1; i <= n; i++)
32     for(j = 1; j <= n; j++)
33       if(i==j) e[i][j]=0;
34         else e[i][j]=99999999;
35           
36   for(i=1;i<=m;i++)
37   {
38      scanf("%d %d %d", &a, &b, &c);
39      e[a][b]=c;
40   }
41  
42   book[1]=1;
43   dfs(1,0);
44   printf("%d",min);
45   
46   getchar(); getchar();
47   return 0;
48 }
49 
50 /*
51 
52 5 8
53 1 2 2
54 1 5 10
55 2 3 3
56 2 5 7
57 3 1 4
58 3 4 4
59 4 5 5
60 5 3 3
61 
62 */

 1 #include <stdio.h>
 2 int min=99999999, book[101], n, e[101][101];
 3 int start,end; //
 4 
 5 void dfs(int cur, int dis)
 6 {
 7   int i;
 8   if(dis>min) return;
 9   if(cur==end) //
10   {
11     if(dis<min) min=dis;
12     return;
13   }
14 
15   for(i=1;i<=n;i++)
16   {
17     if(e[cur][i] !=99999999 && book[i]==0)
18     {
19       book[i]=1;
20       dfs(i,dis+e[cur][i]);
21       book[i]=0;
22     }
23   }
24   return;
25 }
26 
27 int main()
28 {
29   int i,j,m,a,b,c;
30   scanf("%d %d", &n, &m);
31                      
32   for(i = 1; i <= n; i++)
33     for(j = 1; j <= n; j++)
34       if(i==j) e[i][j]=0;
35         else e[i][j]=99999999;
36           
37   for(i=1;i<=m;i++)
38   {
39      scanf("%d %d %d", &a, &b, &c);
40      e[a][b]=c;
41      //e[b][a]=c; //添加这句，使之成为无向图 p141
42   }
43 
44   scanf("%d %d",&start,&end); //最后一行，输入起点与终点
45   book[start]=1; //
46   dfs(start,0); //
47   printf("%d",min);
48   
49   getchar(); getchar();
50   return 0;
51 }
52 
53 /*
54 改编程序，使之能计算任意起点与终点间的最短路径
55 
56 5 8
57 1 2 2
58 1 5 10
59 2 3 3
60 2 5 7
61 3 1 4
62 3 4 4
63 4 5 5
64 5 3 3
65 5 2
66 
67 */

 1 #include <stdio.h>
 2 struct note
 3 {
 4   int x; //城市编号
 5   int s; //转机次数
 6 };
 7 
 8 int main()
 9 {
10   struct note que[2501];
11   int e[51][51]={0}, book[51]={0};
12   int head,tail;
13   int i,j,n,m,a,b,cur,start,end,flag=0;
14   scanf("%d %d %d %d", &n, &m, &start, &end);
15   
16   for(i = 1; i <= n; i++)
17     for(j = 1; j <= n; j++)
18       if(i==j) e[i][j]=0;
19         else e[i][j]=99999999;
20           
21   for(i=1;i<=m;i++)
22   {
23      scanf("%d %d", &a, &b);
24      e[a][b]=1;
25      e[b][a]=1;
26   }  
27   
28   head=1;
29   tail=1;
30   
31   que[tail].x=start;
32   que[tail].s=0;
33   tail++;
34   //book[1]=start;
35   book[start]=1;
36   
37   while(head<tail)
38   {
39     cur=que[head].x;
40     for(i=1;i<=n;i++)
41     {
42       if(e[cur][i]!=99999999 && book[i]==0)
43       {
44         que[tail].x=i;
45         que[tail].s=que[head].s+1;
46         tail++;
47         book[i]=1;
48       }
49       if(que[tail-1].x==end)
50       {
51         flag=1;
52         break;
53       }
54     }
55     if(flag==1) break;
56     head++;
57   }
58   
59   printf("%d\n",que[tail-1].s);
60 
61   getchar(); getchar();
62   return 0;
63 }
64 
65 /*
66 
67 5 7 1 5
68 1 2
69 1 3
70 2 3
71 2 4
72 3 4
73 3 5
74 4 5
75 
76 */