Problem Statement

In a restaurant, if you were pleased by the waiter's service, you may leave him a tip -- you pay him more than the actual value of the bill, and the waiter keeps the excess money. In some countries, not leaving a tip for the waiter is even considered impolite. During my recent holiday I was having dinner in a foreign restaurant. The pamphlet from my travel agency informed me that the proper way of tipping the waiter is the following:

The sum I pay must be round, i.e., divisible by 5.

The tip must be between 5% and 10% of the final sum I pay, inclusive.

Clearly, sometimes there may be multiple "correct" ways of settling the bill. I'd like to know exactly how many choices I have in a given situation. I could program it easily, but I was having a holiday... and so it's you who has to solve this task. You will be given:

an int bill -- the amount I have to pay for the dinner

an int cash -- the amount of money I have in my pocket

Write a function that computes how many different final sums satisfy the conditions above.

Constraints

Assume that both bill and cash are in dollars.

All the money I have is in one-dollar banknotes.

My Code:

int possible_payments(int bill, int cash) {
// fill in code here
int choices;
int counter = 0;
int leftoverCash = cash - bill;
int i = 0;

for (i; i < leftoverCash; i++){
int tipPercent = (i/bill)*100;
int total = i + bill;
if((total % 5 == 0) && (tipPercent <= 10) && (tipPercent >= 5)){
counter++;
}
}

return choices;
}