Submission

Score: 100

User: Kx

Problemset: วันว่างๆ

Language: cpp

Time: 0.031 second

Submitted On: 2026-03-18 12:52:49

#include <bits/stdc++.h>
using namespace std;

typedef vector<pair<int, int>> vpii;

vpii p, sp;

int main() {
    int n; cin >> n;

    while(n--) {
        int m; cin >> m;
        while(m--) {
            int l, r; cin >> l >> r;
            p.push_back({l, r});
        }
    }

    sort(p.begin(), p.end());

    for(auto &[l, r] : p) {
        if(sp.empty() || sp.back().second < l) {
            sp.push_back({l, r});
        } else {
            sp.back().second = max(sp.back().second, r);
        }
    }

    if(sp.size() == 1) {
        cout << -1;
        return 0;
    }

    cout << sp[0].second << ' ';
    for(int i = 1; i < sp.size() - 1; ++i) cout << sp[i].first << ' ' << sp[i].second << ' ';
    cout << sp[sp.size() - 1].first;

    return 0;
}