Dear Zareie

When i compile the code thta you provided in an online aplication and perform a run test y get the following result:

insert number 1                                                                                                                      

1000                                                                                                                                 

insert number 2                                                                                                                      

1                                                                                                                                    

subtraction of numbers is:                                                                                                           

10/9    

I`m not sure if this is the actual error that you're geting, however if that is the case, it appears to be solved by adding some zeros to the smallest number

insert number 1                                                                                                                      

1000                                                                                                                                 

insert number 2                                                                                                                      

0001                                                                                                                                 

subtraction of numbers is:                                                                                                           

0999  

You can add a function that append some zeroes to the samellest number to avoid the error. I hope it helps

Dear Nastaran,

There are various ways to proceed in order to accurately assess the difference between two numbers which have very different orders of magnitude, but working with strings is unlikely to be the easiest approach. The difficulty you are encountering is related to the limited capacity of computers to represent numbers with a finite number of bits, so languages typically define different types of variables to address such issues.

1. If you want to continue use the C language, then you need to learn about double precision variables, or, in the case of integers, variables of type 'long', 'long long', etc. See this article for more details: https://en.wikipedia.org/wiki/C_data_types.

2. Another simple solution may be to use a programming language which can accommodate infinite precision (i.e., which can natively handle such cases). If you are interested in this approach, consider learning Python, which is a very powerful, open source, public domain computer language.

3. If you are constrained to develop your own solution for this problem, consider breaking down your problem as follows: split your very large number (VLN) into a large number (LN) that will not be affected by the subtraction operation and a complementary but manageable number (CN). Then operate your subtraction between that complementary number and your small number (SN), and finally add the partial result (PR) to the large number that you put aside earlier.

In equations:

(1) final result = VLN - SN

(2) final result = (LN + CN) - SN

(3) final result = LN + (CN - SN)

(4) final result = LN + PR

Example:

(1) final result = 12,345,678,901,234 - 1

(2) final result = (12,345,678,901,000 + 234) - 1

(3) final result = 12,345,678,901,000 + (234 - 1)

(4) final result = 12,345,678,901,000 + 233 = 12,345,678,901,233

Note that this approach still hinges on the capacity of the computer to store very large numbers accurately, so in any case you will need to deal with double or quadruple precision numbers.

I hope this helps. Michel.

follow this link https://stackoverflow.com/questions/18454570/how-can-i-subtract-two-strings-in-python

your answer is easy. just try it.

Dear Rebvar karimi

Thanks for your kind answer

But my string contain a big number not word or aomething like that

give me two string like your challenge please