Submission #23207

#	Time	Username	Problem	Language	Result	Execution time	Memory
23207		iletavcioski	Network (BOI15_net)	C++14	100 / 100	659 ms	42516 KiB

net

#include<iostream>
#include<vector>
#include<cstdio>
using namespace std;
vector<vector<int> > v;
int brojac=0;
vector<int> toc;
void dfs(int x,int prev)
{
	
	for(int i=0;i<v[x].size();i++)
		if(v[x][i]!=prev)
		dfs(v[x][i],x);
	if(v[x].size()==1)
		toc.push_back(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;
		scanf("%d %d",&a,&b);
		a--;
		b--;
		v[a].push_back(b);
		v[b].push_back(a);
	}
	brojac=0;
	for(int i=0;i<n;i++)
	{
		if(v[i].size()>1){
			dfs(i,-1);
		break;}
	}
	printf("%d\n",(toc.size()+1)/2);
	for(int i=0;i<(toc.size()+1)/2;i++)
	{
		printf("%d %d\n",toc[i]+1,toc[i+(toc.size())/2]+1);
	}
	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:44:32: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=]
  printf("%d\n",(toc.size()+1)/2);
                                ^
net.cpp:45:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<(toc.size()+1)/2;i++)
               ^
net.cpp:31:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&a,&b);
                       ^

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