Min cost random navigation O(n^2)

#include <iostream>
#include <vector>

using namespace std;

vector<vector<int>> adj;
// costs array
vector<double> C;
vector<double> dp;

//pV is parent of node V
void dfs(int V, int pV){

    //traverse over all children
    double sum=0;
    double count=0;
    for(auto son: adj[V]){
        if(son == pV) continue;
        dfs(son, V);
        sum+=dp[son];
        count++;

    }
    if(count>0)
        sum/=count;
    sum+=C[V];
    dp[V]=sum;
}

int main() {
    ios_base::sync_with_stdio(false);
    int n;
    cin>>n;
    adj=vector<vector<int>> (n);
    C=vector<double> (n,0.0);

    for(int  i=0;i<n-1;i++){
        int x,y;
        cin>>x>>y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for(int  i=0;i<n;i++){
        double cost_Vi;
        cin>>cost_Vi;
        C[i]=cost_Vi;
    }

    int v_strat_best=0;
    double min_cost=100000000;
    for(int i=0;i<n;i++)
    {
        dp=vector<double> (n,0.0);
        dfs(i,-1);
        if(dp[i]<min_cost)
        {
            v_strat_best=i;
            min_cost=dp[i];
        }
    }
    cout << v_strat_best <<" "<< min_cost;


}
/*
 input:
 4
0 1
1 2
1 3
1
1
1
100

output:
1 35
*/