// Returns change to the customer (and out of the machine)
// NOTE: For best results, take advantage of the array of structures.
// The code should then work with any monetary system.
// Hint: Recall the programming question from the first midterm
// which also computed change to return.
// NOTE: The array is there to allow code repetition in a loop.
// For full credit, your implementation must take advantage of that
// Do not return coins the machine does not havr --
// do not leave the machine with a negative number of any coin
// coins (modified struct array) all the types of coins available
// coinTypes (input int) size of coins array
// change (input integer ) amount of change to return
void coinReturn( CoinType coins, int coinTypes, int change )