Submission

[PPPPP][PPPPP][PPPPPPPPPP]

Score: 100

User: Dormon

Problemset: ห้องสมุดเมือง 3M

Language: cpp

Time: 0.003 second

Submitted On: 2025-03-14 15:24:11

#include <iostream>
#include <vector>
#include <map>

using namespace std;

#ifdef DORMON
    #define debug(x) cout << #x << " : " << x << " "
#else
    #define debug(x)
#endif
int main()
{
    int n;
    cin >> n;
    vector<pair<int, int>> v(n);

    int book = 0, lb = 0, ub = 0;
    for (auto &[l, r]:v){
        cin >> l >> r;
        r--;
        book += r - l + 1;
        ub = max(ub, r);
    }

    int med = book / 2, ans = 0;
    if (med == 0){
        cout << v[0].first << '\n';
        return 0;
    }
    while (lb <= ub){
        int mid = lb + (ub - lb) / 2;
        int cnt = 0;
        for (auto [l, r]:v){
            if (mid >= r)
                cnt += r - l + 1;
            else if (mid >= l)
                cnt += mid - l + 1;
            }
        if (cnt >= med){
            ans = mid;
            ub = mid - 1;
        }
        else
            lb = mid + 1;
        debug(lb);
        debug(ub);
        debug(mid);
        debug(cnt);
    }
    cout << ans << '\n';
}