defining codes

I need to write a program for a vending machine where items cost between one cent and one dollar and no larger than a dollar.
It has to give change back in quarters, nickels, dimes, and pennies. Do I need to tell it how to know how many of each to give back and if so how? Also, do I need to make restrictions for the item costs?

Yes and yes. Keep a counter of all your coins and increment everytime you need to give change for that particular type. Post some code if you have problems getting it.