P3905 道路重建

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
const int maxn=110;
int f[maxn][maxn];
int ff[maxn][maxn];
bool hav[maxn][maxn];
int n,m,a,b,c;
int main(){
    memset(f,0x3f3f3f3f,sizeof(f));
    memset(hav,false,sizeof(hav));
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;++i){
        scanf("%d%d%d",&a,&b,&c);
        f[a][b]=0;
        f[b][a]=0;
        ff[a][b]=c;
        ff[b][a]=c;
        hav[a][b]=true;
        hav[b][a]=true;
    }
    scanf("%d",&m);
    for(int i=1;i<=m;++i){
        scanf("%d%d",&a,&b);
        f[a][b]=ff[a][b];
        f[b][a]=f[a][b];
    }
    for(int k=1;k<=n;++k){
        for(int i=1;i<=n;++i){
            for(int j=1;j<=n;++j){
                if(hav[i][k] && hav[k][j]){
                    f[i][j]=min(f[i][j],f[i][k]+f[k][j]);
                    hav[i][j]=true;
                }
            }
        }
    }
    scanf("%d%d",&a,&b);
    printf("%d",f[a][b]);
    return 0;
}