Submission

Score: 100

User: krittaphot

Problemset: วันว่างๆ

Language: cpp

Time: 0.047 second

Submitted On: 2026-03-05 18:57:28

#include <bits/stdc++.h>

using namespace std;

bool cmp(pair<int,int> s1,pair<int,int> s2){
	if(s1.first == s2.first){
		return s1.second > s2.second;
	}
	return s1.first < s2.first;
}

int main()
{
	int n;
	cin >> n;
	int last = -1;
	vector<pair<int,int>> timeline;
	for(int i = 0;i<n;i++){
		int m;
		cin >> m;
		for(int j = 0;j<m;j++){
			int a,b;
			cin >> a >> b;
			timeline.push_back({a,1});
			timeline.push_back({b,-1});
			last = max(last,b);
		}
	}
	
	sort(timeline.begin(),timeline.end(),cmp);
//	for(auto x : timeline){
//		cout << x.first << " " << x.second << "\n";
//	}
	int sum = 0;
	int prev;
	vector<int> ans;
	for(int i = 0;i<timeline.size()-1;i++){
		sum += timeline[i].second;
		if(sum == 0){
			ans.push_back(timeline[i].first);
			ans.push_back(timeline[i+1].first);
		}
	}
	if(ans.size() == 0){
		cout << -1;
	}
	else
		for(int x : ans){
			cout << x << " ";
		}
	
	
}