Submission

Score: 100

User: onlyme910

Problemset: วันว่างๆ

Language: cpp

Time: 0.037 second

Submitted On: 2026-03-11 09:39:14

#include <bits/stdc++.h>

using namespace std;

int main() {
    set<pair<int, int>> time; // starttime and endtime
    

    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        int m;
        cin >> m;
        for (int j = 0; j < m; j++) {
            int a, b;
            cin >> a >> b;


            auto it = time.upper_bound({a, INT_MAX});
            
            if (it != time.begin()) {
                it--;
                if (it -> second < a) {
                    it++;
                }
            }

            while (it != time.end() && it->first <= b) {
                a = min(a, it->first);
                b = max(b, it->second);

                it = time.erase(it);
            }

            time.insert({a, b});


            // for (auto i: time) {
            //     cout << i.first << ' ' << i.second << ' ';
            // }
            // cout << endl;
        }
    }

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

    int cnt = 0;
    for (pair<int, int> i: time) {
        if (cnt == 0) {
            cout << i.second << ' ';
        } else if (cnt+1 == time.size()) {
            cout << i.first;
        } else {
            cout << i.first << ' ' << i.second << ' ';
        }
        cnt++;
    }

}