Submission

Score: 0

User: lazybw_

Problemset: ห้องสมุดเมือง 3M

Language: cpp

Time: 0.002 second

Submitted On: 2025-07-06 12:41:50

#include <bits/stdc++.h>

using namespace std;
using ll = int32_t;

int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    ll n; cin>>n;
    vector<pair<ll,ll>> v(n);
    ll c = 0;
    for (auto &[f, t] : v) cin>>f>>t, c+=t-f;

    ll l = 0, r = 2e7, mid = c/2, ans = 0;
    while (l <= r) {
        ll med = l+(l+r)/2;
        ll cl = 0;
        for (auto &[x, y] : v) {
            cl += max(0, min(med, y-1)-x+1);
        }
        if (cl >= mid) {
                ans = med;
                r = med-1;
        } else l = mid+1;
        // if (cl == c/2) {cout<<mid; return 0;}
        // if (cl *2 < c) {
        //     l = mid+1;
        //     c -= cl;
        // } else {
        //     r = mid-1;
        //     c = cl;
        // } mid = (l+r)/2;
    } cout<<ans;
    return 0;
}