[题解]洛谷P1119 灾后重建

　　链接

　　做死我了，，，半夜找题自虐

　　floyd算法

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<iostream>
#define MAXN 210
#define MAXQ 500010
using namespace std;

int dis[MAXN][MAXN],n,m,t[MAXN],q;
int u[MAXQ],v[MAXQ],qwq[MAXQ];
int b[MAXN]={0};

int read(){
    int x=0,w=1;
    char c=getchar();
    while(c<'0'||c>'9'){
        if(c=='-')w=-1;
        c=getchar();
    }
    while(c>='0'&&c<='9'){
        x=(x<<3)+(x<<1)+c-'0';
        c=getchar();
    }
    return x*w;
}

int main(){
    //freopen("in.in","r",stdin);
    memset(dis,0x7f7f7f7f,sizeof(dis));
    n=read();m=read();
    for (int i=0; i<n; i++)
        dis[i][i]=0;
    for(int i=0;i<n;i++)
        t[i]=read();
    for(int i=1;i<=m;i++){
        int ua=read(),va=read(),wa=read();
        dis[ua][va]=dis[va][ua]=wa;
    }
    q=read();
    for(int i=1;i<=q;i++){
        u[i]=read();v[i]=read();qwq[i]=read();
    }
    for(int kkk=1;kkk<=q;kkk++){
        for(int k=0;k<n;k++)
            if(t[k]<=qwq[kkk]&&!b[k]){
                b[k]=1;
                for(int i=0; i<n; i++)
                    for(int j=0; j<n; j++) 
                        if(dis[i][j]>dis[i][k]+dis[k][j]&&i!=j&&k!=i&&k!=j&&dis[i][k]<0x7f7f7f7f&&dis[k][j]<0x7f7f7f7f)
                            dis[i][j]=dis[i][k]+dis[k][j];
            }
        if(t[u[kkk]]<=qwq[kkk]&&t[v[kkk]]<=qwq[kkk]&&dis[u[kkk]][v[kkk]]!=0x7f7f7f7f)printf("%d\n",dis[u[kkk]][v[kkk]]);
        else printf("-1\n");
    }
    return 0;
}