Submission

Score: 0

User: 555eiei

Problemset: วันว่างๆ

Language: cpp

Time: 0.003 second

Submitted On: 2025-11-05 19:16:35

#include <bits/stdc++.h>

using namespace std;

const int INF = 1e9;

struct A
{
    int s, e;
    bool operator < (const A &o) const {
        if (s != o.s) return s > o.s;
        return e > o.e;
    }
};

int main(){
    cin.tie(nullptr)->sync_with_stdio(0);
    int n; cin >> n;
    priority_queue<A> a;
    for (int i=1; i<=n; i++){
        int m; cin >> m; 
        while (m--){
            A x; cin >> x.s >> x.e;
            a.push(x);
        }
    }
    int lastEnd = -INF;
    vector<int> ans;
    while (!a.empty()){
        A u = a.top(); a.pop();
        if (u.s > lastEnd && lastEnd != -INF){
            ans.push_back(lastEnd);
            ans.push_back(u.s);
        }
        lastEnd = u.e;
    }
    if (ans.empty()) cout << -1;
    for (auto x : ans) cout << x << ' ';
    return 0;
}