#include <iostream>
using namespace std;
 
int reservoirSample(int sample, int* samples, int size, int count)
{
  if(count < size)
    samples[count] = sample;
  else
    if((rand()%count) < size)
      samples[rand()%size] = sample;
   
  return ++count;
}
 
#define SIZE 10
// #define STREAM_AVERAGE 300
#define STREAM_AVERAGE 10
int main()
{
  int count = 0;
  int samples[SIZE];
  int sample;
  int i = 0;
 
  srand(time(NULL));
 
  cout << "Sample Stream: " << endl;
  while(
        (count < SIZE) ||
        (rand()%STREAM_AVERAGE > 0)
        )
    {
      sample = rand()%1000;
      cout << sample << " ";
 
      count = reservoirSample(sample, samples, SIZE, count);
    }
  cout << endl;
  cout << "Total samples: " << count << endl;
 
  cout << "Output samples: " << endl;
  for(i = 0;i < SIZE;i++)
    cout << samples[i] << " ";
  cout << endl;
}