Closest points

//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <queue>
#include <climits>
#include <set>
//#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

ll euclDist(pair<ll,ll> p1, pair<ll,ll> p2){
    return  (p1.first - p2.first) * (p1.first - p2.first) + (p1.second - p2.second) * (p1.second - p2.second);
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    ll n;
    cin >> n ;

    vector<pair<ll,ll>> arr(n);
    for(ll i = 0; i < n; i++){
        cin >> arr[i].first >> arr[i].second;
    }

    sort(arr.begin(), arr.end());

    set<pair<ll,ll>> area;
    ll last = 0;
    ll d = 7999999984000000008;
    for(ll i = 1; i < n; i++){

        pair<ll,ll> p;
        p.first = arr[i-1].second;
        p.second = arr[i-1].first;
        area.insert(p);
         while(last < i){
           if(abs(arr[last].first - arr[i].first) > d){
            area.erase({arr[last].second, arr[last].first});
           } 
            else {
                break;
            }
            last++;
        }

        auto low = area.lower_bound({arr[i].second - d, -LLONG_MAX});
        auto up = area.upper_bound({arr[i].second + d, LLONG_MAX});

       

        while(low != up){
            ll dist = euclDist(arr[i], {low->second, low->first});
            d = min(d, dist);
            ++low;
        }

        
    }

    cout << d << endl;
    return 0;

}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: TIME LIMIT EXCEEDED

Test 4

Verdict: TIME LIMIT EXCEEDED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED