Submission #23204

#	Time	Username	Problem	Language	Result	Execution time	Memory
23204		iletavcioski	Network (BOI15_net)	C++14	0 / 100	0 ms	2024 KiB

net

#include<iostream>
#include<vector>
using namespace std;
vector<vector<int> > v;
int brojac=0;
vector<int> toc;
void dfs(int x,int prev)
{
	if(v[x].size()==1)
		toc.push_back(x);
	for(int i=0;i<v[x].size();i++)
		if(v[x][i]!=prev)
		dfs(v[x][i],x);
}
int main()
{
	int n;
	cin>>n;
	vector<int> vec;
	v.insert(v.begin(),n+1,vec);
	if(n==1)
	{
		cout<<0<<endl;
		return 0;
	}
	for(int i=0;i<n-1;i++)
	{
		int a,b;
		cin>>a>>b;
		a--;
		b--;
		v[a].push_back(b);
		v[b].push_back(a);
	}
	brojac=0;
	dfs(0,-1);
	if(toc.size()%2)
	{
		toc.push_back(toc[0]);
	}
	cout<<(int)(toc.size())/2<<endl;
	for(int i=0;i<toc.size()-1;i+=2)
	{
		cout<<toc[i]+1<<" "<<toc[i+1]+1<<endl;
	}
	return 0;
}

Compilation message (stderr)

net.cpp: In function 'void dfs(int, int)':
net.cpp:11:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<v[x].size();i++)
               ^
net.cpp: In function 'int main()':
net.cpp:42:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<toc.size()-1;i+=2)
               ^

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