PPT Slide
Let us call the operation number_and_balance().
public static int[] number_and_balance(int amount, int coin_size)
/* Computes number_of_coins and balance remaining after removal of
number_of_coins * coin_size from int amount and returns number_of_coins
in int result[0] and balance in int result[1]*/
/* precondition: 0 >amount 0 > coin_size > 25; */
/* postcondition: result[0] = amount/coin_size;
result[1] = amount - result[0] *coin_size; */
int[] result = new int[2];
result[0] = amount/coin_size;
result[1] = amount % coin_size;
Definition of an appropriate abstract operation