Submission

Score: 100

User: njoop

Problemset: ห้องสมุดเมือง 3M

Language: cpp

Time: 0.202 second

Submitted On: 2025-03-09 23:39:27

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

int n, l, r, cnt[20000010], book[20000010], dif, to;
vector<int> books;

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    cin >> n;
    for(int i=1; i<=n; i++) {
        cin >> l >> r;
        cnt[l]++;
        cnt[r]--;
        to += r-l;
    }
    book[0] = cnt[0];
    dif = cnt[0];
    if(book[0] > to/2-1 && book[0] != 0) {
        cout << 0;
        return 0;
    }
    for(int i=1; i<=20000000; i++) {
        dif += cnt[i];
        book[i] = book[i-1] + dif;
        if(to == 1 && cnt[i] == 1) {
            cout << i;
            return 0;
        } 
        if(book[i-1] <= to/2-1 && book[i] > to/2-1) {
            cout << i;
            return 0;
        }
    }
    return 0;
}