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