【codevs2011】【LNOI2013】最小距离之和

floyed水题

 

 1 #include<algorithm>
 2 #include<iostream>
 3 #include<cstdlib>
 4 #include<cstring>
 5 #include<cstdio>
 6 #include<cmath>
 7 using namespace std;
 8 
 9 #define INF 30000000
10 #define N 210
11 
12 struct Node
13 {
14     int f,t,v;
15     int ans;
16 }e[N];
17 
18 int g[N][N];
19 
20 int n,m;
21 
22 int main()
23 {
24     scanf("%d",&n);    
25     for (int i=1;i<=n;i++)
26         for (int j=1;j<=n;j++)
27             scanf("%d",&g[i][j]);
28     scanf("%d",&m);    
29     for (int i=1;i<=m;i++)
30     {
31         scanf("%d%d",&e[i].f,&e[i].t);
32         e[i].v=g[e[i].f][e[i].t];
33         g[e[i].f][e[i].t]=INF;
34     }
35     for (int k=1;k<=n;k++)
36         for (int i=1;i<=n;i++)
37             for (int j=1;j<=n;j++)
38                 g[i][j]=min(g[i][j],g[i][k]+g[k][j]);
39         for (int i=1;i<=n;i++)
40         for (int j=1;j<=n;j++)
41             e[m].ans+=g[i][j];
42     for (int k=m;k>=1;k--)
43     {
44         for (int i=1;i<=n;i++)
45             for (int j=1;j<=n;j++)
46                 g[i][j]=min(g[i][j],g[i][e[k].f]+g[e[k].t][j]+e[k].v);   
47         for (int i=1;i<=n;i++)
48             for (int j=1;j<=n;j++)
49                 e[k-1].ans+=g[i][j];
50     }
51     for (int i=1;i<=m;i++)
52         if (e[i].ans>=INF)
53             printf("INF\n");
54         else
55             printf("%d\n",e[i].ans);
56     return 0;
57 }

 

posted @ 2016-04-11 22:09  Yangjiyuan  阅读(175)  评论(0)  编辑  收藏  举报