【codevs2011】【LNOI2013】最小距离之和

floyed水题

 #include<algorithm>
 #include<iostream>
 #include<cstdlib>
 #include<cstring>
 #include<cstdio>
 #include<cmath>
 using namespace std;

 #define INF 30000000
 #define N 210

 struct Node
 {
     int f,t,v;
     int ans;
 }e[N];

 int g[N][N];

 int n,m;

 int main()
 {
     scanf("%d",&n);
     for (int i=;i<=n;i++)
         for (int j=;j<=n;j++)
             scanf("%d",&g[i][j]);
     scanf("%d",&m);
     for (int i=;i<=m;i++)
     {
         scanf("%d%d",&e[i].f,&e[i].t);
         e[i].v=g[e[i].f][e[i].t];
         g[e[i].f][e[i].t]=INF;
     }
     for (int k=;k<=n;k++)
         for (int i=;i<=n;i++)
             for (int j=;j<=n;j++)
                 g[i][j]=min(g[i][j],g[i][k]+g[k][j]);
         for (int i=;i<=n;i++)
         for (int j=;j<=n;j++)
             e[m].ans+=g[i][j];
     for (int k=m;k>=;k--)
     {
         for (int i=;i<=n;i++)
             for (int j=;j<=n;j++)
                 g[i][j]=min(g[i][j],g[i][e[k].f]+g[e[k].t][j]+e[k].v);
         for (int i=;i<=n;i++)
             for (int j=;j<=n;j++)
                 e[k-].ans+=g[i][j];
     }
     for (int i=;i<=m;i++)
         if (e[i].ans>=INF)
             printf("INF\n");
         else
             printf("%d\n",e[i].ans);
     return ;
 }