Help on pointer math please =)

[pnob32]

Hey guys I am getting an error that I just cant figure out in this code:

http://http://pastebin.com/9anaBP6f

the error is:
change.c:34: error: pointer value used where a floating point value was expected
change.c:36: error: pointer value used where a floating point value was expected
change.c:38: error: pointer value used where a floating point value was expected

I'm just now learning how to use pointers so i apologize if I am completely off on syntax =/

thanks for any sort of help =)

[nimitzhunter]

your problem is this

 amount = amount - 0.25 * (double)quarters;

change it to

 amount = amount - 0.25 * ( double( *quarters) );

[pnob32]

sorry I didnt realize the link didnt work...
heres the code

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

void coin_change(double amount, int *quarters, int *dimes, int *nickels, int *pennies);

int
main()
{
        double price, pay, coins = 0;
        int dollars, *quarters, *dimes, *nickels, *pennies;

        printf("Welcome to the COINCOUNTER >9000!\n");

        printf("Input the amount due (0 to quit):  ");
        scanf("%lf", &price);
        printf("Input the amount paid:  ");
        scanf("%lf", &pay);

        printf("Your change is: \n");

        dollars = ceil(pay - price);
        printf("dollars: %d\n", dollars);

        coins = pay - price - dollars;

        coin_change(coins, quarters, dimes, nickels, pennies);

        return (0);
}

void coin_change(double amount, int *quarters, int *dimes, int *nickels, int *pennies)
{
        *quarters = amount/0.25;
        amount = amount - 0.25 * (double)quarters;
        *dimes = amount/0.1;
        amount = amount - 0.1 * (double)dimes;
        *nickels = amount/0.05;
        amount = amount - 0.05 * (double)nickels;
        *pennies = ceil(amount/0.01);

        printf("quarters: %d\ndimes: %d\nnickels: %d\npennies: %d\n", *quarters, *dimes, *nickels, *pennies);
}

[pnob32]

ok, fixed that problem
now I'm getting a segmentation fault when I call the function coin_change

[nimitzhunter]

because you have not allocated memory for them. it's better you just declare them to be int instead of pointer to int, then pass the address to the function.

int quarter; 
coin_change( something, &quarter, something);

[pnob32]

Awesome! =)
thanks so much