#include<iostream>
#include <algorithm>
#include <vector>
using namespace std;
double double_random() {
  // poor random numbers 0...1
  return rand()*1.0/RAND_MAX; // avoid int/int ! 
}
int main() {
  vector<double> v(20);
  // fill vector with random numbers
  generate(v.begin(), v.end(), double_random); 
  // output
  for(unsigned i=0; i<v.size(); ++i){
    cout<<i<<"  "<<v[i]<<endl; 
  }
}