HOJ-1007

 1 #include<cstdio>
 2 #include<cstring>
 3 
 4 #define MAXN 1010
 5 
 6 struct point{
 7   int ref, nex;
 8 };
 9 
10 point a[MAXN];
11 int head[MAXN];
12 bool vis[MAXN];
13 
14 void runn(int k){
15   vis[k] = true;
16   int i = head[k];
17   while(i > 0){
18     if(!vis[a[i].ref]) runn(a[i].ref);
19     i = a[i].nex;
20   }
21 }
22 
23 int main(void)
24 {
25   int x, y;
26   int k;
27   int n, m;
28   int N = 1;
29   bool p, q;
30   q = false;
31   scanf("%d", &x);
32   while(x > 0){
33     if(q) printf("\n");
34     else q = true;
35     memset(head, 0, sizeof(head));
36     printf("Network #%d\n", N++);
37     p = true;
38     k = 1;
39     n = 0;
40     while(x > 0){
41       scanf("%d", &y);
42       a[k].ref = y;
43       a[k].nex = head[x];
44       head[x] = k++;
45       a[k].ref = x;
46       a[k].nex = head[y];
47       head[y] = k++;
48       if(x > n) n = x;
49       if(y > n) n = y;
50       scanf("%d", &x);
51     }    //printf("** n = %d", n);
52     for(int i = 0; i <= n; ++i){　　//这里出现了0，以及下方出现了if(i == 0) break;是为了判断图是否连通，仅仅是后来加的补丁，所以比较非主流
53       memset(vis, false, sizeof(vis));
54       vis[i] = true;
55       m = 0;
56       for(int j = 1; j <= n; ++j)
57     if(!vis[j]){
58       runn(j);
59       m++;
60     }
61       if(m > 1) {
62     if(i == 0) break;//←←←←这里
63     printf("  SPF node %d leaves %d subnets\n", i, m);
64     p = false;
65       }
66     }
67     if(p) printf("  No SPF nodes\n");
68     //printf("\n");
69     scanf("%d", &x);
70   }  
71   return 0;
72 }