CSES – Restaurant Customers

#include<bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define f first
#define s second
#define fastio ios_base::sync_with_stdio(0);cin.tie(0)
using namespace std;
//declare
int n;
map<int,int> diff;
//
signed main(){
    fastio;
    cin>>n;
    while(n--){
        int a,b; cin>>a>>b;
        diff[a]++;
        diff[b+1]--;
    }
    int sum = 0, ans = 0;
    for(auto [_,x] : diff){
        sum += x;
        ans = max(ans, sum);
    }
    cout<<ans<<"\n";
    return 0;
}