Submission #2554871

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Source Code Expand

#include<iostream>
#include<vector>

using namespace std;

#define LL long long int

struct edge{
    LL next;
    LL cost;
};

vector<vector<edge>> vec(100001);
vector<LL> total(100001,0);
vector<bool> close(100001,false);

void dfs(int r){
    close[r] = true;
    for(int i = 0; i < vec[r].size(); i++){
        if(!close[vec[r][i].next]){
            total[vec[r][i].next] = total[r] + vec[r][i].cost;
            dfs(vec[r][i].next);
        }
    }
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;

    cin >> n;

    for(int i = 0; i < n-1; i++){
        LL a,b,c;
        cin >> a >> b >> c;
        vec[a].push_back(edge{b,c});
        vec[b].push_back(edge{a,c});
    }

    int q,k;

    cin >> q >> k;

    vector<int> qx(q),qy(q);

    for(int i = 0; i < q; i++){
        cin >> qx[i] >> qy[i];
    }

    dfs(k);

    for(int i = 0; i < q; i++){
        cout << total[qx[i]] + total[qy[i]] << "\n";
    }

    return 0;
}

Submission Info

Judge Result