Help with this java program

**Daredevilpwn** · 09-27-2012 03:35 AM

Hello guys. In my computer programming class I need to make a program that can compute the pocket change of any number specified by the user. So for example if I were to input 1.30 in the program it should output something like
"You have 5 quarters"
"You have one nickels"
"You have 0 dimes"
"You have 0 pennies"

I understand this is most likely the most simplest question but I am stumped right now.
What would be an appropriate algorithm for this task?

**Supernova** · 09-27-2012 03:57 AM

Well, I don't know anything about Java in particular (my class is using C++), but as far as general logic, I would start by converting the decimal amount to cents, then divide by the value of a quarter and round that figure down to an integer. That integer becomes your number of quarters, and you then subtract that number times 25 form the total. Repeat for each coin until the remaining amount is 0. There, I did your homework.

As my instructor said, "Programming is an art, not a science."

**Daredevilpwn** · 09-27-2012 04:06 AM

Thanks, I understand now. Good luck with your c++ class
and yeah I agree, programming is indeed an art.

**Supernova** · 09-27-2012 04:29 AM

Thanks, good luck with your java class! And, I say that (he says that) because it is in many ways open to interpretation, depending on how you the programmer want to do something - for example, there is not one correct way to implement the outline I gave above. It's all about creative problem solving, a very fun sort of puzzle.

**jarrhead** · 02-01-2013 05:35 AM

From what I know of javascript, I would create an object called "Quarter," "Dime," etc. Assign a value to each object (0.25, 0.10...) then create an ask box for each object, where the user inputs the number value of how many coins they have of each. "How many quarters do you have?" "How many dimes do you have?"

From here, it would look something like

Code:

Quarters * [ask value] + Dimes * [dimes ask value] ...

It's been forever so I can't tell you the specific operators for things like the ask value. Only the logical process I would do for a simple program to calculate this.

Also, this is javaSCRIPT, not java. Not sure if my answer is of any help, which is why I gave a process of logic rather than code.

**Oros** · 02-01-2013 08:03 AM

Originally Posted by jarrhead

Also, this is javaSCRIPT, not java. Not sure if my answer is of any help, which is why I gave a process of logic rather than code.

What is the difference between javascript and java? I thing I've heard that it's a different scripting language, but that sound illogical, why not rename it completely then? How could you notice it was javascript and not java? Java = huge piece of code that make up a program/app/whatever?

**jarrhead** · 02-01-2013 01:22 PM

Originally Posted by Oros

What is the difference between javascript and java? I thing I've heard that it's a different scripting language, but that sound illogical, why not rename it completely then? How could you notice it was javascript and not java? Java = huge piece of code that make up a program/app/whatever?

I put in the words "not sure" because I've been told they're not the same and I only know a little bit of javascript. I know nothing of java. For all I know it could be another language entirely. That's also why I only laid out an answer in logic rather than code.

**Shrek** · 02-02-2013 04:28 PM

The simplest algorithm would divide 1.30 by .25, output the amount to be the quarters, divide the remainder by .10, output the remainder to be number of dimes, and so on.

**Replicon** · 02-02-2013 05:23 PM

I assume this is only meant to support the standard american change (quarters, dimes, nickels and pennies). Then, it's super easy.

0) Define the values of each coin in pennies (since you're in Java, the cleanest way to do this is to define a Coin enum, and then your QUARTER can have a value of 25, etc. Java enums are really versatile since version 1.5).
1) Convert input to pennies (assuming you don't have to worry about input validation or anything, all you have to do is multiply by 100, and perhaps round to the nearest int just for posterity).
2) For each coin value, in decreasing order (start with quarters, then dimes, etc.) figure out how many coins fit in how much is left, and then: output your line, subtract the right amount, and keep moving.

I'm being a bit vague because this is your homework and you should at least have to think about it a little bit.

I will say that if you setup your enum properly and just define a list or array of coins in the correct order, you won't need to repeat any code. Just loop over them.