Submission

[PP-SS][SSSSS][SSSSSSSSSS]

Score: 0

User: ftm

Problemset: ห้องสมุดเมือง 3M

Language: cpp

Time: 0.002 second

Submitted On: 2025-03-13 03:04:27

#include<bits/stdc++.h>
using namespace std;
#define f(i,a,b,c) for(int i=a;i<=b;i+=c)
#define r(i,a,b,c) for(int i=a;i>=b;i-=c)
#define fi first
#define se second
#define pb push_back
using ll=long long int;
using pii=pair<int,int>;
const int N=1e2+2;
const int M=1e9+7;
array<int,2> d[N];

int main(){
	ios::sync_with_stdio(0); cin.tie(0);
	int n;cin>>n;
	ll R=0;
	f(i,1,n,1) {
		cin>>d[i][0]>>d[i][1];
		R+=d[i][1]-d[i][0];
	}
	ll k=R/2;
	ll l=1,r=R;
	//cout<<R<<","<<k<<"\n";
	while(l<r){
		ll m=(l+r)/2;
		ll t=0;
		f(i,1,n,1){
			if(d[i][0]<=m){
				t+=min(1ll*d[i][1]-1,m)-d[i][0]+1;
			}
		}
		//cout<<m<<" "<<t<<"\n";
		if(t<k) l=m+1;
		else r=m;
	}
	cout<<l;
}
/*
2
0 5
5 15

6
*/