Submission #102145

#	Time	Username	Problem	Language	Result	Execution time	Memory
102145		Leonardo_Paes	Network (BOI15_net)	C++11	0 / 100	3 ms	384 KiB

net

#include <bits/stdc++.h>

using namespace std;

const int MAXN = 5e5 + 100;

int grau[MAXN];

int main(){

    int n;

    cin >> n;

    for(int i=1; i<n; i++){
        int a, b;

        cin >> a >> b;

        grau[a]++;
        grau[b]++;
    }

    vector<int> v;

    for(int i=1; i<=n; i++){
        if(grau[i]==1){
            v.push_back(i);
        }
    }

    int ans = (v.size()+1)/2;

    cout << ans << "\n";

    for(int i=0; i<ans-1; i++){
        cout << v[i] << " " << v[i+ans] << "\n";
    }
    if(v.size()&1){
        cout << v[ans-1] << " " << v[0] << "\n";
    }
    else{
        cout << v[ans-1] << " " << v[v.size()-1];
    }
    return 0;
}

• Subtask 1: 0 / 18
• Subtask 2: 0 / 45
• Subtask 3: 0 / 37