Submission #85212

#	Time	Username	Problem	Language	Result	Execution time	Memory
85212		Mahmoud_Adel	Network (BOI15_net)	C++14	0 / 100	14 ms	12464 KiB

net

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
const int N = 5e5+5;
vector<int> adj[N];
int main()
{
    int n;
    cin >> n;
    for(int i=0; i<n-1; i++)
    {
        int x, y;
        cin >> x >> y;
        x--, y--;
        adj[x].push_back(y), adj[y].push_back(x);
    }
    vector<int> vec;
    for(int i=0; i<n; i++) if(adj[i].size() == 1) vec.push_back(i);
    if(vec.size()%2)
    {
        cout << vec.size()/2 + 1 << endl;
        cout << vec[0]+1 << " " << vec[1]+1 << endl;
        for(int i=1; i<vec.size()-1; i+=2) cout << vec[i]+1 << " " << vec[i+1]+1 << endl;
    }
    else
    {
        cout << vec.size()/2 << endl;
        for(int i=0; i<vec.size()-1; i+=2) cout << vec[i]+1 << " " << vec[i+1]+1 << endl;
    }
}

Compilation message (stderr)

net.cpp: In function 'int main()':
net.cpp:23:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=1; i<vec.size()-1; i+=2) cout << vec[i]+1 << " " << vec[i+1]+1 << endl;
                      ~^~~~~~~~~~~~~
net.cpp:28:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0; i<vec.size()-1; i+=2) cout << vec[i]+1 << " " << vec[i+1]+1 << endl;
                      ~^~~~~~~~~~~~~

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