Submission #49445

#	Time	Username	Problem	Language	Result	Execution time	Memory
49445		faishol27	Network (BOI15_net)	C++14	0 / 100	3 ms	644 KiB

net

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

#define PUB push_back

int N;
int way[500005];
vector<int>leaf;

int main(){
	cin >> N;
	for(int i = 0;i<N-1;i++){
		int x, y;
		cin >> x >> y;
		way[x]++;
		way[y]++;
	}

	for(int i=1;i<=N;i++) if(way[i]==1) leaf.PUB(i);
	if(leaf.size()%2 == 1) leaf.PUB(1);

	cout << leaf.size()/2 << endl;
	for(int i=0;i<leaf.size();i+=2){
		cout << leaf[i] << " " << leaf[i+1] << endl;
	}
}

Compilation message (stderr)

net.cpp: In function 'int main()':
net.cpp:23:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<leaf.size();i+=2){
              ~^~~~~~~~~~~~

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