Town center

#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <queue>
#include <climits>
using namespace std;
typedef long long ll;

void dijkstra2(const vector<vector<pair<long long,long long>>> &adj, long long start, vector<long long> &dist) {
    long long n = adj.size();
    vector<bool> processed(n, false);
    dist.assign(n, 0);
    priority_queue<pair<long long,long long>> pq;
    dist[start] = 9223372036854775807;
    pq.push({0, start});

    while (!pq.empty()) {
        long long a = pq.top().second;
        pq.pop();
        if (processed[a]) continue;
        processed[a] = true;

        for (auto [b, w] : adj[a]) {
            if(dist[b] < min(dist[a],w)) {
            dist[b] = min(w,dist[a]);
            pq.push({dist[b], b});
            }
        }
    }
}

ll dijkstra(const vector<vector<pair<long long,long long>>> &adj, long long start, vector<long long> &dist) {
    long long n = adj.size();
    dist.assign(n, LLONG_MAX);
    vector<bool> processed(n, false);

    priority_queue<pair<long long,long long>, vector<pair<long long,long long>>, greater<pair<long long,long long>>> pq;
    dist[start] = 0;
    pq.push({0, start});
    ll commulted = 0;

    while (!pq.empty()) {
        long long a = pq.top().second;
        pq.pop();
        if (processed[a]) continue;
        processed[a] = true;

        for (auto [b, w] : adj[a]) {
            if (dist[a] + w < dist[b]) {
                if(dist[b] != LLONG_MAX)
                    commulted -= dist[b];
                dist[b] = dist[a] + w;
                commulted += dist[b];

                pq.push({dist[b], b});
            }
        }
    }
    return commulted;
}

void task2(){
ll n, q;
    cin >> n >> q;

    vector<vector<pair<ll,ll>>> adj(n+1, vector<pair<ll,ll>>(n+1));
    for(ll i = 1; i <= n; i++){
        for(ll j = 1; j <= n; j++){
            ll a;
            cin >> a;
            adj[i][j] = make_pair(j,a);
        }
    }
    vector<vector<ll>> maxKeel(n+1, vector<ll>(n+1,0));

    for(ll i = 1; i <= n; i++){
        vector<ll> dist;
        dijkstra(adj, i, dist);
        
        maxKeel[i] = dist;
    }
    for(ll i = 1; i <= q; i++){
        ll a,b;
        cin >> a >> b;
        cout << maxKeel[a][b] << endl;
    }
}

void task3(){
    ll n, m;
    cin >> n >> m;

    vector<vector<pair<ll,ll>>> adj(n);
    for(ll i = 0; i < m; i++){

        ll a ,b;
        cin >> a >> b;
        a--;
        b--;
        adj[a].push_back( make_pair(b,1) );
        adj[b].push_back( make_pair(a,1) );
        
    }

    




    vector<double> avr(n+1,LLONG_MAX);

    for(ll i = 0; i < n; i++){
        vector<ll> dist;
        ll com =  dijkstra(adj, i, dist);
        //cout << com << endl;
        ///for(ll j = 0; j < n; j++){

          //  cout << dist[j] << " ";
        //}
        //cout << endl;
        avr[i] = double(com) / double(n);
    }
    


        /*ll sum = 0;
        for(ll j = 1; j <= n; j++){
            sum += dist[j];
            //cout << dist[j] << endl;
        }*/
        //avr[i] = sum / (double(n));
       //cout << avr[i] << " ";
        //cout << double(com) / double(n) << endl;
        
    


    double minVal = LLONG_MAX;
    int index = -1;
    for(ll i = 0; i < n; i++){
        if(avr[i] < minVal){
minVal = avr[i];
index = i;
        } 
        //cout << avr[i] << " ";
    }
    cout << index+1 << endl;

}



int main() {
    
task3();
    
    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

Test 66

Verdict: ACCEPTED

Test 67

Verdict: ACCEPTED

Test 68

Verdict: ACCEPTED

Test 69

Verdict: ACCEPTED