Submission

Score: 100

User: 12345678

Problemset: ห้องสมุดเมือง 3M

Language: cpp

Time: 0.002 second

Submitted On: 2025-06-17 22:24:14

#include <bits/stdc++.h>

using namespace std;

#define ll long long

const int nx=105;

ll n, x[nx], y[nx], sm;

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n;
    for (int i=1; i<=n; i++) cin>>x[i]>>y[i], y[i]--, sm+=(y[i]-x[i]+1);
    if (sm==1) return cout<<x[1], 0;
    ll l=0, r=2e7;
    while (l<r)
    {
        ll md=(l+r)/2, cur=0;
        for (int i=1; i<=n; i++)
        {
            if (md<x[i]) continue;
            if (md>=y[i]) cur+=(y[i]-x[i]+1);
            else cur+=(md-x[i]+1);
        }
        //cout<<"dbg "<<md<<' '<<cur<<'\n';
        if (cur>=sm/2) r=md;
        else l=md+1;
    }
    cout<<l;
}