Submission #748406

#	Time	Username	Problem	Language	Result	Execution time	Memory
748406		mariowong	Network (BOI15_net)	C++14	0 / 100	1 ms	332 KiB

net

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

int deg[100005]; 
int main(){
	ios::sync_with_stdio(false); 
	int n;
	cin >> n;
	for (int i=1;i<n;i++){
		int u,v;
		cin >> u >> v;
		deg[u]++; deg[v]++;
	}	
	int cnt=0;
	for (int i=1;i<=n;i++){
		if (deg[i] == 1) cnt++;
	}
	cout << (cnt+1)/2 << "\n";
	int node=0; 
	for (int i=1;i<=n;i++){
		if (deg[i] == 1){
			if (node == 0) node=i;
			else{
				cout << node << " " << i << "\n";
				node=0; 
			} 
		} 
	}
	for (int i=1;i<=n;i++){
		if (deg[i] == 1 && node != 0){
			cout << node << " " << i << "\n";
			break; 
		} 
	} 
	return 0;
}

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