Set difference

Problem :  Given 2 arrays such that second is the subset of the first, find the set difference.
That is all the elements in array1 that are not in array2.
Eg:  
array1 - 6 7 4 3 9 1 2 5 8 0
array2 - 1 2 3 5 4
Set difference - 6 7 9 8 0

#include<stdio.h>

int main()
{
  int s1, s2, i, j, k = 0, check, a1[50], a2[50], a3[50];
  printf("\nEnter the size of array1:");
  scanf("%d", &s1);
  printf("\nEnter the elements\n");
  for(i = 0; i < s1; i++)
    scanf("%d", &a1[i]);
  printf("\nEnter the size of array2 < size of array1:");
  scanf("%d", &s2);
  printf("\nEnter the elements (should be a subset of array1)\n");
  for(i = 0; i < s2; i++)
    scanf("%d", &a2[i]);

  for(i = 0; i < s1; i++)
  {
    check = 1;
    for(j = 0; (j < s2 && check == 1); j++)
    {
      if(a1[i] != a2[j])
        continue;
      else
        check = 0;
    }
    if(check == 1)
      a3[k++] = a1[i];
  }
  printf("\nSet difference:\n");
  for(i = 0; i < k; i++)
    printf("%d ", a3[i]);

  return 0;
}

Written by Munia Balayil