Submission

Score: 100

User: someone

Problemset: ห้องสมุดเมือง 3M

Language: cpp

Time: 0.007 second

Submitted On: 2026-03-06 11:06:10

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

int main() {
    int n, maxSize = 0;
    cin >> n;
    map<int, int> book;
    int first = 0;
    for (int i = 0 ; i < n ; i++) {
        int x, y;
        cin >> x >> y;
        book[x]++;
        book[y]--;
        maxSize += y-x;
        first = x;
    }
    if (maxSize == 1) {
        cout << first;
        return 0;
    }
    int prev = 0;
    int cntBook = 0;
    int cnt = 0;

    for (auto p : book) {
        int index = p.first;
        cntBook += (index-prev)*cnt;
        if (cntBook >= maxSize/2) {
            cntBook -= (index-prev)*cnt;
            for (int i = prev ; i < index ; i++) {
                cntBook += cnt;
                if (cntBook >= maxSize/2) {
                    cout << i;
                    return 0;
                }
            }
        }
        cnt += p.second;
        prev = index;
    }
}