poj 2387 最短路模板题

 1 #include <cstdio>
 2 #include <cstring>
 3 #include <iostream>
 4 #include <algorithm>
 5 #include <vector>
 6 #include <queue>
 7 #include <set>
 8 #include <map>
 9 #include <string>
10 #include <cmath>
11 #include <stdlib.h>
12 #define MAXSIZE 1005
13 using namespace std;
14 
15 int t,n;
16 int m[MAXSIZE][MAXSIZE],dis[MAXSIZE],vis[MAXSIZE];
17 
18 void dij(int s)
19 {
20     int i,j,k;
21     for(i = 0;i<n;i++)
22     {
23         dis[i] = m[s][i];
24         vis[i] = 0;
25     }
26     dis[s] = 0;
27     vis[s] = 1;
28     for(i = 1;i<=n;i++)
29     {
30         k = 0;
31         int mn = 1000000;
32         for(j = 1;j<=n;j++)
33             if(!vis[j]&&dis[j]<mn)
34             {
35                 mn = dis[j];
36                 k = j;
37             }
38         vis[k] = 1;
39         for(j = 1;j<=n;j++)
40             if(!vis[j]&&dis[j]>dis[k]+m[k][j])
41                 dis[j] = dis[k]+m[k][j];
42     }
43 }
44 
45 int main()
46 {
47     freopen("caicai.txt","r",stdin);
48     cin>>t>>n;
49     int i,j,a,b,w;
50     for(i = 0;i<=n;i++)
51         for(j = 0;j<=n;j++)
52             m[i][j] = 1000;
53     for(i = 0;i<t;i++)
54     {
55         scanf("%d%d%d",&a,&b,&w);
56         if(m[a][b]>w)
57         {
58             m[a][b] = w;
59             m[b][a] = w;
60         }
61     }
62     dij(n);
63     cout<<dis[1]<<endl;
64     return 0;
65 }