95C

跑dijiestra每个点的最短路径

#include<iostream>
#include<Vector>
#include<cstring>
#include<queue>
#include<cstdio>
#define mp make_pair
using namespace std;
typedef long long ll;
typedef pair<ll,ll> PII;
const ll inf=(ll)(1e15);
priority_queue<PII,vector<PII>,greater<PII> >q;
ll n,m,x,y,u,v,w,tar,t,c,val;
ll dis[][];
ll used[],d[];
vector<PII>graph[];
void dijiestra1(int a)
{
    for(int i=;i<=n;i++) d[i]=inf;
    memset(used,,sizeof(used));
    d[a]=;
    q.push(mp(,a));
    while(!q.empty())
    {
        PII x=q.top();q.pop();
        int u=x.second;
        if(used[u]) continue;
        used[u]=;
        for(int i=;i<graph[u].size();i++)
        {
            x=graph[u][i];
            int v=x.first,val=x.second;
            if(d[v]>d[u]+val){d[v]=d[u]+val;q.push(mp(d[v],v));}
        }
    }
}
int main()
{
    cin>>n>>m;
    cin>>x>>y;
    for(int i=;i<=m;i++)
    {
        scanf("%d%d%d",&u,&v,&val);
        graph[u].push_back(mp(v,val));
        graph[v].push_back(mp(u,val));
    }
    for(int i=;i<=n;i++)
    {
        dijiestra1(i);
        for(int j=;j<=n;j++) dis[i][j]=dis[j][i]=d[j];
    }
    for(int i=;i<=n;i++) graph[i].clear();
    for(int i=;i<=n;i++)
    {
        scanf("%d%d",&t,&c);
        for(int j=;j<=n;j++) if(dis[i][j]<=t) graph[i].push_back(mp(j,c));
    }
    dijiestra1(x);
    if(d[y]==inf) d[y]=-;
    cout<<d[y]<<endl;
    return ;
}