[模板]Dijkstra

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <ctime>
 5 using namespace std;
 6 int n, map[510][510], dis[510];
 7 bool exist[510];
 8 int dij(int x, int y){
 9     dis[x] = 0;
10     for (int i = 1; i <= n; i++){
11         int k = 0, minn = 0x5f;
12         for (int j = 1; j <= n; j++)
13             if (exist[j] == false && dis[j] < minn)
14                minn = dis[j], k = j;
15                if (k == 0) break;
16                exist[k] = true;
17                for (int j = 1; j <= n; j++)
18                    if (dis[j] > dis[k] + map[k][j])
19                       dis[j] = dis[k] + map[k][j]; 
20     }
21     return dis[y];
22 }
23 int main(){
24     scanf("%d", &n);
25     for (int i = 1; i <= n; i++)
26         for (int j = 1; j <= n; j++)
27             scanf("%d", &map[i][j]);
28     int t;
29     scanf("%d", &t);
30     while (t--){
31         int x, y;
32         scanf("%d%d", &x, &y);
33         memset(dis, 0x3f, sizeof(dis));
34         memset(exist, false, sizeof(exist));
35         printf("%d\n", dij(x, y));
36     }
37     return 0;
38 }