Submission

Score: 100

User: Nay-O

Problemset: วันว่างๆ

Language: cpp

Time: 0.031 second

Submitted On: 2026-03-26 14:06:34

#include<bits/stdc++.h>
using namespace std;
using pii = pair<int,int>;

priority_queue<pii,vector<pii>,greater<pii>> pq;

int main(){
	ios_base::sync_with_stdio(false); cin.tie(NULL);
	
	int n; cin>>n;
	for(int i = 0; i < n; i++){
		int m; cin>>m;
		while(m--){
			int a,b; cin>>a>>b;
			pq.push({a,-1}); pq.push({b,1});
		}
	}
	int c = 0;
	vector<int> ans;
	
	while(!pq.empty()){
		if(ans.size()%2==1){
			ans.push_back(pq.top().first);
		}
		c-=pq.top().second;
		if(c==0){
			ans.push_back(pq.top().first);
		}
		pq.pop();
	}
	ans.pop_back();
	
	for(auto value : ans){
		cout << value << " ";
	}
	
	if(ans.size()==0){
		cout << -1;
	}
	
	return 0;
}