remove duplicates from Array Elements

write a program to remove duplicates from ordered and unordered Array Elements 

#include<stdio.h>

int main() {

   int arr[20], i, j, k, size;

    printf("\nEnter array size : ");

   scanf("%d", &size);

    printf("\nAccept Numbers : ");

   for (i = 0; i < size; i++)

      scanf("%d", &arr[i]);

    printf("\nArray with Unique list  : ");

   for (i = 0; i < size; i++) {

      for (j = i + 1; j < size;) {

         if (arr[j] == arr[i]) {

            for (k = j; k < size; k++) {

               arr[k] = arr[k + 1];

            }

            size--;

         } else

            j++;

      }

   }

   for (i = 0; i < size; i++) {

      printf("%d ", arr[i]);

   }

   return (0);

}