Submission #394711

#	Time	Username	Problem	Language	Result	Execution time	Memory
394711		MHNaderi	Network (BOI15_net)	C++14	0 / 100	1 ms	204 KiB

net

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define int long long
#define pb push_back
#define pii pair<int,int>
#define F first
#define S second
const int maxn=5e5+7;
int n,d[maxn];
void preprocess(){
    cin>>n;
    for(int i=1;i<n;i++){
        int u,v;
        cin>>u>>v;
        d[u]++;
        d[v]++;
    }
}
vector<int> ans;
void process(){
    for(int i=1;i<=n;i++)
        if(d[i] % 2)
            ans.pb(i);
}
void afterprocess(){
    cout<<ans.size()/2<<'\n';
    for(int i=0;i<ans.size();i+=2)
        cout<<ans[i]<<' '<<ans[i+1]<<'\n';
}
int32_t main(){
	ios_base::sync_with_stdio(0);
	preprocess();process();afterprocess();

	return 0;
}

Compilation message (stderr)

net.cpp: In function 'void afterprocess()':
net.cpp:32:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |     for(int i=0;i<ans.size();i+=2)
      |                 ~^~~~~~~~~~~

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