Submission

Score: 100

User: vachirasawin

Problemset: ห้องสมุดเมือง 3M

Language: cpp

Time: 0.067 second

Submitted On: 2026-03-12 23:16:04

// grader-chan
// c2_ds66_3m.cpp | c2_ds66_3m

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

int n;
int x, y;
int curr = 0;
int total = 0, tmp = 0;
vector<int> books(20000001);

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    cin >> n;

    while (n--) {
        cin >> x >> y;

        books[x]++;
        books[y]--;
        curr = max(curr, y);
        total += y - x;
    }

    if (total == 1) {
        cout << x;
        return 0;
    }

    for (int i = 0; i < curr + 2; i++) {
        if (i != 0) books[i] += books[i - 1];

        tmp += books[i];

        if (tmp >= total / 2) {
            cout << i;
            return 0;
        }
    }

    return 0;
}