Trying to write a simple Calculation program.

[PaladinHammer]

This thing is pushing me around. I've been through my book, and I have even downloaded the professor's notes on subject (he posted them). I can't find what I'm doing wrong. Below is the code I've written, below the code is what the console is "supposed" to look like.

(Code begins here):

#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;

int main()
{
int price, amountpaid;
float change;
cout << "Please give the price of the item (example: $5.95).\n";
cin >> price;

while (price > 0.00)
{
cout << "Please enter the amount you wish to pay\n";
cin >> amountpaid;
if (amountpaid <=0)
{
cerr << "Invalid input, program closing\n";
exit (1);
}
if (amountpaid < price)
{
cout << " You still owe " << price - amountpaid << " dollars ";
}
if (amountpaid >=0)
change= amountpaid-price; 

cout << " You will recieve " << change << " dollars in change." << endl;
exit (1);
}
return 0;
}

(Code ends here)

For some reason I cannot put any number with a decimal in for "price" or "amountpaid". Also, The change is supposed to show up as WHAT change is being recieved, example:
1 Ten
2 Fives
0 Ones
2 Quarters
0 Dimes
0 Nickels
1 Penny

No matter what I've tried to do, I can't get farther than the above code. Can anyone help me?

Note: I've understood that somehow, "modulo" operators are needed here. But I haven't the foggiest idea how to use them! Can anyone, with great detail, tell me how I could use them here?

[iamthwee]

> For some reason I cannot put any number with a decimal in for "price" or "amountpaid".
You need to declare the type double > But I haven't the foggiest idea how to use them!
Google it, but for your information the percentage sign is the modulus operator.

[PaladinHammer]

I know that the "%" sign is the modulus operator. The problem is, HOW to use it to get the code I'm looking for?

Is it:

(change % 20 == 0)?
I haven't the slightest idea. I've goolged "how to use modulo operators", and all I've gotten is the basic: "11 % 3 = 2" (2 being a remainder).

[iamthwee]

Plan it out on paper or draw a flow chart if necessary.

[PaladinHammer]

How will that help?

[iamthwee]

>How will that help?

Well a program is just a flow chart really, that's why.

[PaladinHammer]

>How will that help?

Well a program is just a flow chart really, that's why.

I know what I'm after, I don't know WHAT or HOW.

What I've been typing:

change = Penny % 100;
change = Nickel % 20;
change = Dime % 10;
change = Quarter % 4;

and so on

That doesn't work. I don't know how to use modulos operators in the sense that I want the remainders to be used later so that I can get the full amount of money. All the guides I've found from google just use modulos "%" once in the program, I need to use it eight times!

[VernonDozier]

If you are going to use the modulo operator, convert everything to cents first. So, say you are trying to figure out how many ten dollar bills are in $38.45. Ten dollars is 1000 cents. $38.45 is 3845 cents. You use the / operator to calculate the number of tens:

int numTens = 3845 / 1000;

Result? numTens will equal 3.

Now for the rest of your change, after you give out the three tens, which is worth $30.00, you'll have $38.45 - $30.00 = $8.45 remaining, or 845 cents. To get THAT, you use the % operator:

int numCentsRemaining = 3845 % 1000;