Submission #533815

#	Time	Username	Problem	Language	Result	Execution time	Memory
533815		groshi	Network (BOI15_net)	C++17	100 / 100	359 ms	47672 KiB

net

#include<iostream>
#include<vector>
using namespace std;
struct wi{
    vector<int> Q;
}*w;
vector<int> mam;
void dfs(int x,int ojc)
{
    if(w[x].Q.size()==1)
        mam.push_back(x);
    for(int i=0;i<w[x].Q.size();i++)
    {
        int pom=w[x].Q[i];
        if(pom==ojc)
            continue;
        dfs(pom,x);
    }
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n,x,y;
    cin>>n;
    w=new wi[n+3];
    for(int i=1;i<n;i++)
    {
        cin>>x>>y;
        w[x].Q.push_back(y);
        w[y].Q.push_back(x);
    }
    for(int i=1;i<=n;i++)
    {
        if(w[i].Q.size()>1)
        {
            dfs(i,0);
            break;
        }
    }
    cout<<(mam.size()+1)/2<<"\n";
    for(int i=0;i<(mam.size()+1)/2;i++)
        cout<<mam[i]<<" "<<mam[i+mam.size()/2]<<"\n";
    return 0;
}

Compilation message (stderr)

net.cpp: In function 'void dfs(int, int)':
net.cpp:12:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |     for(int i=0;i<w[x].Q.size();i++)
      |                 ~^~~~~~~~~~~~~~
net.cpp: In function 'int main()':
net.cpp:43:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |     for(int i=0;i<(mam.size()+1)/2;i++)
      |                 ~^~~~~~~~~~~~~~~~~

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