6G network

input/code.cpp: In function 'bool isConnected(double, ll, std::vector<std::pair<double, double> >&)':
input/code.cpp:77:23: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   77 |     return res.size() == n;
      |            ~~~~~~~~~~~^~~~

#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 <bits/stdc++.h>
using namespace std;
typedef long long ll;

void task1(){
    ll n;
    cin >> n;

    ll a,b;
    vector<pair<ll,ll>> arr(n + 1);
    for(ll i = 0; i < n; i++){
        cin >> a >> b;
        arr[i] = {a,b};
    }
    arr[n] = arr[0];
    ll sum = 0;
    for(ll i = 0; i < n; i++){
        sum += (arr[i].first * arr[i+1].second) - (arr[i+1].first * arr[i].second);
       // cout << arr[i].first << " " << arr[i+1].second << endl;
       // cout << arr[i+1].first << " " << arr[i].second << endl;

    }
    cout << abs(sum) << endl;
}

double euclDist(pair<double,double> p1, pair<double,double> p2){
    return sqrt( pow((p1.first - p2.first),2) + pow((p1.second - p2.second),2) );
}

void bfs(vector<vector<int>>& adj, vector<ll> &res) {
    int V = adj.size();
    vector<bool> visited(V, false);
    
    queue<int> q;
    
    int src = 0;
    visited[src] = true;
    q.push(src);

    while (!q.empty()) {
        int curr = q.front();
        q.pop();
        res.push_back(curr);
        
        for (int x : adj[curr]) {
            if (!visited[x]) {
                visited[x] = true;
                q.push(x);
            }
        }
    }
}

bool isConnected(double dist, ll n, vector<pair<double,double>>& arr){
    vector<vector<int>> adj(n);
    
    for(ll i = 0; i < n; i++){
        for(ll j = i + 1; j < n; j++){
            if(euclDist(arr[i], arr[j]) <= dist){
                adj[i].push_back(j);
                adj[j].push_back(i);
            }
        }
    }
    
    vector<ll> res;
    bfs(adj, res);
    return res.size() == n;
}

double binarySearch(vector<pair<double,double>> &arr, ll n) {
    double low = 0;
    double high = 200000.0; 
    double epsilon = 1e-9;
    
    while (high - low > epsilon) {
        double mid = low + (high - low) / 2;

        if (isConnected(mid, n, arr)) {
            high = mid;
        } else {
            low = mid;
        }
    }

    return low;
}




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

    vector<pair<double,double>> arr(n);

    for(ll i = 0; i < n; i++){
        double a, b;
        cin >> a >> b;
        arr[i] = {a, b};
    }

    double result = binarySearch(arr, n);
    cout.precision(20);
    
    cout << result << endl;

    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

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

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: ACCEPTED

Test 43

Verdict: ACCEPTED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: ACCEPTED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: ACCEPTED

Test 51

Verdict: ACCEPTED

Test 52

Verdict: ACCEPTED

Test 53

Verdict: ACCEPTED

Test 54

Verdict: ACCEPTED

Test 55

Verdict: ACCEPTED

Test 56

Verdict: ACCEPTED

Test 57

Verdict: ACCEPTED

Test 58

Verdict: ACCEPTED

Test 59

Verdict: ACCEPTED

Test 60

Verdict: ACCEPTED

Test 61

Verdict: ACCEPTED

Test 62

Verdict: ACCEPTED

Test 63

Verdict: ACCEPTED

Test 64

Verdict: ACCEPTED

Test 65

Verdict: ACCEPTED