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Thread: PEMDAS Calculator

  1. #1
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    Question PEMDAS Calculator

    I'm writing a calculator, and to start, I'm writing basic arithmetic functionality. I've figured out how to tackle the "EMDAS" portion of the Order of Ops, however, I don't have a clue on how to simplify parentheses. The code I've written doesn't work in that regard, though everything else so far works great. How would you guys do the parentheses?

    pseudo-code which needs revising/reworking (I've written actual code, but it's fairly confusing...)
     
    solveParentheses(String[] equation):
     
    loop until no more parentheses:
     
    find first parenthesis
    store its location in a variable
     
    find close parenthesis 
    store its location in a variable
     
          If found one but not the other, give error message
     
    save the content of the parentheses into an array
     
    that array = solveParentheses(that array)
     
    simplify order of ops inside parentheses
     
    set the location of end parenthesis to result of simplification
     
    set indices between the first parenthesis and result to "null" 
     
    :end loop
     
    count number of null values
     
    new array of length equation.length-nullcounter
     
    fill array with non-null values
     
    return array
     
    :end function


  2. #2
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    Default Re: PEMDAS Calculator

    7 + 3 infix
    7 3 + postfix

    The easiest way to evaluate infix equations is to convert them to post fix first.
    Improving the world one idiot at a time!

  3. #3
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    Default Re: PEMDAS Calculator

    That's not how my algorithm works... Care to elaborate?

  4. #4
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    Default Re: PEMDAS Calculator

    Maybe its not how YOUR algorithm works but I suggested a different algorithm you can use. Have you bothered to Google "infix to postfix"?
    Improving the world one idiot at a time!

  5. #5
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    Default Re: PEMDAS Calculator

    Yes, I still don't know what it does.

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