Submission #228139

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Source Code Expand

#include <iostream>
#include <vector>
#include <algorithm>
#include<iomanip>
using namespace std; 

int main(){
  int N;

  cin >> N;
  vector<int> data(N);

  for(int i=0; i < N; ++i){
    cin >> data[i];
  }

  double sum = 0.0;

  for(int i = 0;i < N;i++){
	  int count = 0;
	  for(int j = 0;j < N;j++){
		  if(!(data[i] % data[j]))
			  count++;
	  }
	  count--;
	  sum += ((double)(count / 2 + 1)) / ((double)count + 1.0);
  }


  cout <<fixed << setprecision(12) << sum << endl;

  return 0;

}

Submission Info

Judge Result