Submission #41218

#	Time	Username	Problem	Language	Result	Execution time	Memory
41218		wzy	Network (BOI15_net)	C++14	0 / 100	10 ms	12132 KiB

net

#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define int long long // LEMBRAR DE TROCAR CASO PROBLEMA DE MEMORIA
#define pii pair<int,int>
#define ieps (int) 1e6
#define eps (int) 1e9
#define mp make_pair
#define pb push_back


int n;
vector<int> adj[500005];
vector<int> ans;





int32_t main(){
	int n;
	cin>>n;
	int root = 0;
	for(int i = 0 ; i <n - 1; i++){
		int x ,y;
		cin>>x>>y;
		adj[x].pb(y);
		adj[y].pb(x);
		root = x;
	}
	for(int i = 1 ; i <=n ; i++){
		if(adj[i].size() == 1) ans.pb(i);
	}
	cout<< (ans.size()/2) + (ans.size()%2) << endl;
	for(int i = 0  ; i <( ans.size() / 2 + ans.size()%2) ; i++){
		if(i == ans.size()/2 && (ans.size())%2){
			cout<<ans[i] <<" " << ans[0]<<endl;
			continue;
		}
		cout<<ans[i] <<" " << ans[ans.size() - i - 1]<<endl;
	}
}

Compilation message (stderr)

net.cpp: In function 'int32_t main()':
net.cpp:36:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0  ; i <( ans.size() / 2 + ans.size()%2) ; i++){
                     ^
net.cpp:37:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i == ans.size()/2 && (ans.size())%2){
        ^
net.cpp:24:6: warning: variable 'root' set but not used [-Wunused-but-set-variable]
  int root = 0;
      ^

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