Submission

Score: 100

User: VggT

Problemset: วันว่างๆ

Language: cpp

Time: 0.029 second

Submitted On: 2026-03-13 21:32:16

#include <bits/stdc++.h>
using namespace std;
int main()
{
	int n; cin >> n;
	vector<pair<int,int>> ans;
	map<int,int> m;
	int busy = 0, start = -1;
	
	for(int i = 0; i < n; i+=1)
	{
		int num; cin >> num;
		for(int j = 0; j < num; j+=1)
		{
			int n1,n2; cin >> n1 >> n2;
			m[n1]+=1;
			m[n2]-=1;
		}
	}
	
	for(auto a : m)
	{
		if(busy == 0 && start != -1)
		{
			ans.push_back({start,a.first});
		}
		busy+=a.second;
		
		if(busy == 0)
		{
			start=a.first;
		}
	}
	
	if(ans.empty()) cout << -1;
	else
	{
		for(auto a : ans)
		{
			cout << a.first << ' ' << a.second << ' ';
		}
	}
	
	return 0;
}