Restaurant Customers.cpp

#include<bits/stdc++.h>
using namespace std;
#define INF 2147483647
#define INFL 9223372036854775807
#define pii pair<int,int>
#define F first
#define S second
#define mp make_pair
#define pb push_back
#define ll long long
#define ull unsigned long long
#define M 1000000007
#define FASTIO ios_base::sync_with_stdio(false);cin.tie(NULL); cout.tie(NULL);
#define take(x) scanf("%d",&x)
#define DE(x) printf("\ndebug %d\n",x);
#define vout(x) for(int i=0;i<x.size();i++) printf("%d ",x[i]);
#define pie acos(-1)
#define MOD 998244353

int main(){
    FASTIO;
    int n;
    take(n);
    int starts[n],ends[n];
    for(int i=0;i<n;i++){
        take(starts[i]);
        take(ends[i]);
    }
    sort(starts,starts+n);
    sort(ends,ends+n);
    int i = 0, j = 0;
    int mx = 0;
    int curr = 0;
    while(i<n and j<n){
        if( starts[i]<ends[j] ){
            curr++;
            i++;
        } else if(starts[i]>ends[j]){
            curr--;
            j++;
        } else{
            i++;
            j++;
        }
        mx = max(mx,curr);
    }
    printf("%d",mx);
}