cash.c

#include <cs50.h>
#include <stdio.h>
#include <math.h>

int main(void)
{
    //create a variable to hold value of coins
    int coins = 0;
    //get change amount
    float change = get_float("Change owed: ");
    //if change is greater than 0
    if (change > 0)
    {
        //convert amount to cents
        int cents = round(change * 100);
        do 
        {
            // if cents are greater than or equal to denomination
            if (cents >= 25)
            {
                // subtract the denominational value
                cents -= 25;
                // add 1 to coins
                coins++;
            }
            else if (cents >= 10)
            {
                cents -= 10;
                coins++;
            }
            else if (cents >= 5)
            {
                cents -= 5;
                coins++;
            }
            else if (cents >= 1)
            {
                cents -= 1;
                coins++;
            }
        } 
        while (cents >= 1);
        printf("%i\n", coins);
    }
    // if change is a negative number or not a float
    // call the function again
    else if (!change || change < 0)
    {
        main();
    };
}