Submission #405182

#	Time	Username	Problem	Language	Result	Execution time	Memory
405182		T0p_	Network (BOI15_net)	C++14	0 / 100	1 ms	304 KiB

net

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

int deg[500005];

int main()
{
	int n;
	scanf(" %d",&n);
	for(int i=1 ; i<n ; i++)
	{
		int u, v;
		scanf(" %d %d",&u,&v);
		deg[u]++, deg[v]++;
	}
	vector<int> v;
	for(int i=1 ; i<=n ; i++)
		if(deg[i] == 1) v.push_back(i);
	int sz = v.size();
	printf("%d\n",(sz+1)>>1);
	for(int i=1 ; i<sz ; i+=2)
		printf("%d %d\n",v[i-1],v[i]);
	if(sz%2) printf("%d %d\n",v[sz-2], v[sz-1]);
	return 0;
}

Compilation message (stderr)

net.cpp: In function 'int main()':
net.cpp:9:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |  scanf(" %d",&n);
      |  ~~~~~^~~~~~~~~~
net.cpp:13:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |   scanf(" %d %d",&u,&v);
      |   ~~~~~^~~~~~~~~~~~~~~~

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