Submission

Score: 0

User: havename

Problemset: เดินทางข้ามชุมชน

Language: cpp

Time: 0.003 second

Submitted On: 2026-03-07 11:44:35

#include<bits/stdc++.h>
using namespace std;
#define ll long long

int findroot(vector<ll>& prt,int st){
    if(prt[st]==st) return st;
    return prt[st]=findroot(prt,prt[st]);
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n,m,q;
    cin>>n>>m>>q;
    vector<pair<ll,pair<ll,ll>>> edgs;
    vector<ll> prt(n+1);
    for(int i=0;i<n;i++){
        prt[i]=i;
    }

    for(int i=0;i<m;i++){
        int a,b,c;
        cin>>a>>b>>c;
        edgs.push_back({c,{a,b}});
    }
    vector<pair<pair<ll,ll>,pair<ll,ll>>> value;
    for(int i=0;i<q;i++){
        int st,ed,cost;
        cin>>st>>ed>>cost;
        value.push_back({{st,i},{st,ed}});


    }
    vector<bool> ans(q,false);
    int l=0;
    sort(value.begin(),value.end());
    sort(edgs.begin(),edgs.end());
    for(int i=0;i<q;i++){
        ll cost=value[i].first.first;
        ll st=value[i].second.second;
        ll ed=value[i].second.first;
        ll idx=value[i].first.second;
        while(l<m && edgs[l].first<=cost){
            ll a=edgs[l].second.first;
            ll b=edgs[l].second.second;
            ll A=findroot(prt,a);
            ll B=findroot(prt,b);
            if(A!=B){
                prt[A]=B;
                
            }
            l++;
        }
        if(findroot(prt,st)==findroot(prt,ed)){
            ans[idx]=true;
        }
    }
    for(int i=0;i<q;i++){
        if(ans[i]) cout<<"Yes\n";
        else cout<<"No\n";
    }


}