Most Popular Friend

#include <bits/stdc++.h>
using namespace std;

int main() {
	// your code goes here
	int t;
	cin>>t;
	while(t--)
	{
	    int n,m_popu=INT_MIN;
	    cin>>n;
	    
	    vector<int> size;
	    vector<vector<int>> g(n,vector<int>(n,101));
	    
	    for(int i=0;i<n;i++)
	        g[i][i]=0;
	        
	    string s;
	    getline(cin,s);     //removeing '\n'
	    for(int i=0;i<n;i++){
	        getline(cin,s);    
	        
	        int val=0;
	        for(int j=0;j<s.length();j++){
	            if(s[j]==' ' || j==s.length()-1){
	                if(j==s.length()-1)
	                    val=(val*10)+(s[j]-'0');
	                    
	                g[i][val-1]=1;
	                val=0;
	            }
	            else
	                val=(val*10)+(s[j]-'0');    //converting string to int
	        }
	    }
	    
	    for(int k=0;k<n;k++){
	        for(int i=0;i<n;i++){
	            for(int j=0;j<n;j++)
	                g[i][j]=min(g[i][j],g[i][k]+g[k][j]);
	        }
	    }
	    
	    int ans;
	    double avg=1000000.0;
	    for(int i=0;i<n;i++){
	        double sum=0;
	        for(auto& x:g[i])
	            sum+=x;
	            
	        double z=(double)sum/n;
	        
	        if(z < avg){
	            avg=z;
	            ans=i;
	        }
	    }
	    cout<<ans+1<<" "<<fixed<<setprecision(6)<<avg<<endl;
	}
	return 0;
}