How to Calculate Quotient and Remainder in Embedded

[jsureshp]

Hi......
I want to calculate the Quotient and remainder in embedded c.
please anybody give the formula for the Mathematical calculation...
Please provide that formula with example
that will help to easily to understand..............

 

[doraemon]

Hello!

Here are the 2 ints to process: a, b
Here is the quotient and remainder: q, r

What about this:
q = a / b;
r = a % b;

And for the second line, here is a variant:

r = a - b * q;

Dora.

 

[jsureshp]

Hi
Thanks for Reply............


I can't understand the following line...

And for the second line, here is a variant:

r = a - b * q;

can you explain with example.... please...
for example a=45
b=10;
then
Quotient q=45/10=4.5 But here the quotient is floating point... is our embedded system will take only 4 ? or 4.5....
That is my dought

Remainder r=45 % 10= 5

 

[Tahmid]

Hi,
This means that

r = a % b;

can also be written as

r = a - b * q;

You should use

r = a % b;

as it is easier to understand when you go through the code.

Explaining the statement

r = a - b * q;

:
Let's take your example, so a = 45, b = 10

q = a / b;

q=45/10 = 4
So, a-b*q = a-(b*q) = 45-(10*4) = 45 - 40 = 5

So, q stores 4 - the quotient,
r stores 5 - the remainder.

Hope this helps.
Tahmid.

 

[doraemon]

Hello!

Quotient q=45/10=4.5

If you use float numbers, then you will never get a remainder.
That's why I assumed that you were talking about integer numbers.

In C, if you divide 2 integers, then you will get the integral part only.
Not only in embedded C, just try it in plain C on Windows, you will get the
same result. With your numbers:

int a, b, q, r;

a = 45;
b = 10;

q = a/b; // At this point you get q = 4

r = a % b; // Modulus operation gives you the remainder.

And another way to "manually" calculate it is:

r = a - b * q;
With the same numbers:

r = 45 - (4 * 10) = 5;

Does it make sense now?

Dora.