Submission #666760

#	Time	Username	Problem	Language	Result	Execution time	Memory
666760		divad	Network (BOI15_net)	C++14	0 / 100	7 ms	12056 KiB

net

#include <iostream>
#include <algorithm>
#include <vector>
#define MAX 500002
using namespace std;
int n,x,y,vf[MAX];
vector<int> v[MAX],frunze;

void dfs(int nod){
    vf[nod] = 1;
    bool ok = false;
    for(auto vecin: v[nod]){
        if(vf[vecin] == 0){
            ok |= true;
            dfs(vecin);
        }
    }
    if(!ok){
        frunze.push_back(nod);
    }
}

int main()
{
    cin >> n;
    for(int i = 1; i < n; i++){
        cin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    dfs(1);
    sort(frunze.begin(), frunze.end());
    cout << frunze.size()-1 << "\n";
    cout << "1 " << frunze[0] << "\n";
    for(int i = 1; i < frunze.size()-1; i++){
        cout << frunze[i] << " " << frunze[i+1] << "\n";
    }
    return 0;
}

Compilation message (stderr)

net.cpp: In function 'int main()':
net.cpp:35:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |     for(int i = 1; i < frunze.size()-1; i++){
      |                    ~~^~~~~~~~~~~~~~~~~

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