Question

I have generated code that counts the minimum number of 20’s, 10’s, 5’s, 2’s and 1’s that will add up to a user defined amount of money. The user is only allowed to enter whole numbers i.e. no decimal values. I have two questions.

1. If a denomination is not needed, the program outputs a random number instead of 0. How can I fix this?
2. Is it possible to create a function that could replace all of the if statements and possibly the printf statements? I’m new to functions so am a little bit lost with them.

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main(void)
{
 int pounds;
 int one, two, five, ten, twenty;

    printf("Enter a pounds amount with no decimals, max E999999: \n");
    scanf("%d", &pounds);
    printf("%d\n", pounds);

    if(pounds >= 20)
    {
        twenty = (pounds / 20);
        pounds = (pounds-(twenty * 20));
        printf("%d\n", pounds);
    }
    if(pounds >= 10)
    {
        ten = (pounds / 10);
        pounds = (pounds-(ten * 10));
        printf("%d\n", pounds);
    }
    if(pounds >= 5)
    {
        five = (pounds / 5);
        pounds = (pounds-(five * 5));
        printf("%d\n", pounds);
    }
    if(pounds >= 2)
    {
        two = (pounds / 2);
        pounds = (pounds-(two * 2));
        printf("%d\n", pounds);
    }
    if(pounds >= 1)
    {
        one = (pounds / 1);
        pounds = (pounds-(one * 1));
        printf("%d\n", pounds);
    }


 printf("The smallest amount of denominations you need are: \n");
 printf("20 x %d\n", twenty);
 printf("10 x %d\n", ten);
 printf("5 x %d\n", five);
 printf("2 x %d\n", two);
 printf("1 x %d\n", one);

return 0;
}

Answer 1

This is a great example of why you should initialize your variables when you declare them.

If pounds<20, then twenty will never get initialized. In C, variables have a (basically) random value assigned to them until you replace it with something else.

You just need to do this:

int one = 0, two = 0, five = 0, ten = 0, twenty = 0;