/*
 * This program takes a sample of the specified size (SIZE_OF_SAMPLES)
 * from integers between 0 and a MAX value (ends inclusive) without
 * replacement.  Contains bugs to practice debugging.
 */

#include <stdio.h>
#include <stdlib.h>

#define MAX             6
#define SIZE_OF_SAMPLES 3
#define REP             5

int MemberQ(int *array, int arrSize, int x);
void UniqRandInts(int max, int howmany, int * resultPtr);

int main(void) {
  int arr[SIZE_OF_SAMPLES], i, j, max, size;

  srand(9808);
  max = MAX;
  size = SIZE_OF_SAMPLES;

  for (i = 0; i < REP; i++) {
    UniqRandInts(max, size, arr);
    for(j = 0; j < size; j++) {
      printf("%d ", arr[j]);//swap arr[i] with arr[j]
    }
    printf("\n");
  }
  return 0;
}

/*
 * resultPtr[] will be initialized with a sample of the specified size
 * (n) from integers between 0 and a max value (ends inclusive)
 * without replacement.
 */
void UniqRandInts(int max, int n, int *resultPtr) {
  int cntr = 0, r;

  while(cntr < n) {
    r = rand();
    r = r % (max + 1);
    if (MemberQ(resultPtr, cntr, r)) {
      resultPtr[cntr] =  r;
      cntr++;
    }
  }
  return;
}

/*
 * Check if an integer x is included in array[] of arrSize.
 * Returns: 1 if x is a member
 *          0 if x is not a member
 */
int MemberQ(int *array, int arrSize, int x) {
  int i;

  for (i = 0; i < arrSize; i++) {
    if (array[i] == x) {
      return 0;//not a member should be 0 instead of 1
    }
  }
  return 1;//return 1 because it is a member
}