I d like some tips before starting coding a calculator that can calculate expression such as

"3 + 52 * ( 1 - 3 / (3 + 7) - 1 % 21) + 19"

i need it to calculate with the five operators (+ - * / %) and respect the parentheses "()"

at the moment i don't have much clue so any help is welcome !

I am not sure the BEST way to go about this, but my suggestion would be to read it as a string, and then search the string for the order you want things to be done. After evaluating parenthesis, replace that part of the string with the answer. A recursive function to check through the order. Maybe later I'll break it down into a working example but a bit busy now.

thx for the advice , still hard to see how and where to start , but i m working on it !

just some random thoughts based on what Snickerfritzer said:

perhaps look for every occurrence of "(" and ")"
generate a depth "score" for each one.


depth = 0
every time you find a "(" add 1 to the depth score and record it for that occurance
every time you find a ")" subtract 1 from the depth score

find the "(" with the largest depth value, and evaluate everything you find until you reach the next ")". Remove the "(" and the ")" then rinse repeat.

This post was edited by Azrad on Aug 29 2013 05:58pm

that sounds like a good idea , i ll work on that to see if i can get anything from it
what is funny when we start c is that it takes 2days to do omething like that when an average developper need like 1h30min

this might help

http://www.smccd.net/accounts/hasson/C++2Notes/ArithmeticParsing.html

yes helps a lot to understand the algo, but it s in c++. I think i ll do it without taking the parentheses into consideration because it makes it really difficult for someone of my lvl

This post was edited by anezk on Aug 31 2013 04:49am

the c++ code is only for postfix which isn't relevant anyway.

Doesn't c++ already incorporate parentheses into ooo