c++ class help

[Wilhelm4]

Hi, I havent been to these forums in years, but I'm in a programming 1010 class and I cannot figure out one small part on the assignment, I was hoping someone here would see what I'm missing. I have all the functions and code written and working, it is just the math that I cant get right for the following objective:
"The delivery charge for the first pound (i.e., 16 ounces) is $3.00 and $0.50 is added to the charge for each additional 4 ounces. For example, a package weighing more that 16 ounces but at most 20 ounces costs $3.50 to deliver; a package weighing more than 20 but at most 24 ounces costs $4.00 to deliver; etc."

Here is the code i wrote for this:

Code: Select all

double price;
int over16;

over16 = ((oz - 16)/4);
over16 = over16 + 1;

if (oz <= 16)
price = 3.00;
else
price = 3.00 + (over16 /2)

This code works properly for every number except 20, 24, 28, 32....

Is there possibly any way that I can tell over16 that if the answer is an integer when it does the calculations (and its already defined as one), it will not add 1 to itself? That is the only problem, I just have no idea how to achieve this.

Does anyone have any suggestions for how I can fix this? I have been looking at it for a few days and nothing has popped into my brain yet. Thanks in advance for any help.

[avansc]

fuck it.

Code: Select all

#include <math.h>

double calc(int oz)
{
	if(oz > 16)
	{
		 return 3.0 + 0.5 * ceil(((double)oz-16)/4);
	}else
		return 3.0;
}

[Wilhelm4]

That did the trick, after a little playing around with it i got it to work. Thanks for the help avansc.

1 question:

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int oz;

(double)(oz/2)

Does that make it so the integer oz will display a decimal (if its odd of course)?

[avansc]

That did the trick, after a little playing around with it i got it to work. Thanks for the help avansc.

1 question:

Code: Select all

int oz;

(double)(oz/2)

Does that make it so the integer oz will display a decimal (if its odd of course)?

well no that cast is useless by it self.
lets say oz = 3 then 3/2 is gonna give you 2 seeing as oz is of type int.

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int oz;

(double)oz/2

that is 1.5

[wtetzner]

Or if you don't want to cast, you could just use 2.0.

Code: Select all

int oz;

oz/2.0

[avansc]

Or if you don't want to cast, you could just use 2.0.

Code: Select all

int oz;

oz/2.0

i prefer doing it this way to, but our coding standards force us to do casts, especially code that will be maintained by someone else. i guess its just for readability.