POJ 2387 Til the Cows Come Home

 1 #include <stdio.h>
 2 #include <string.h>
 3 #define inf 999999999
 4 int visit[1010];
 5 int dis[1010];
 6 int p[1010][1010];
 7 int n;
 8 int dijkstra()
 9 {
10     int i,j,pos = 0,minn;
11     memset(visit,0,sizeof(visit));
12     visit[1] = 1;
13     dis[1] = 0;
14     for (i = 2; i <= n; i ++)
15         dis[i] = p[1][i];
16     for (i = 1; i <= n; i ++)
17     {
18         minn = inf;
19         for (j = 1; j <= n; j ++)
20         {
21             if (!visit[j] && dis[j] < minn)
22             {
23                 minn = dis[j];
24                 pos = j;
25             }
26         }
27         visit[pos] = 1;
28         for (j = 1; j <= n; j ++)
29             if (!visit[j] && dis[j] > dis[pos]+p[pos][j])
30                 dis[j] = dis[pos]+p[pos][j];
31     }
32     return dis[n];
33 }
34 int main ()
35 {
36     int t,a,b,c,i,j;
37     while (~scanf("%d%d",&t,&n))
38     {
39         for (i = 1; i <= n; i ++)
40             for (j = 1; j <= n; j ++)
41                 p[i][j] = inf;
42 
43         for (i = 0; i < t; i ++)
44         {
45             scanf("%d%d%d",&a,&b,&c);
46             if (p[a][b] > c)
47                 p[a][b] = p[b][a] = c;
48         }
49         printf("%d\n",dijkstra());
50     }
51     return 0;
52 }