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Thread: Stacks (evaluating postfix expression)

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    Default Stacks (evaluating postfix expression)

    I'm a little confused so if someone can confirm if I am doing that would be great.

    Evaluate postfix expression:

    1 2 + 4 * 5 6 * 10 / 8 * +

    Me evaluating:

    1) 1
    2) 2 1
    3) 3
    4) 4 3
    5) 12
    6) 5 12
    7) 6 5 12
    8) 30 12
    9) 10 30 12
    10) Here's where I get confused. Do I do 30/10 or 10/30 (and is it the same way for subtraction)...3 12
    11) 8 3 12
    12) 24 12
    13) 36


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    Default Re: Stacks (evaluating postfix expression)

    From Wikipedia:

    Operations which are non-commutative are still written in "conventional order", i.e.:

    a b op = a op b

    4 2 / = 4 / 2 = 2
    2 4 / = 2 / 4 = 0.5

  3. The Following User Says Thank You to helloworld922 For This Useful Post:

    dx8292 (October 6th, 2012)

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    Default Re: Stacks (evaluating postfix expression)

    Quote Originally Posted by helloworld922 View Post
    From Wikipedia:

    Operations which are non-commutative are still written in "conventional order", i.e.:

    a b op = a op b

    4 2 / = 4 / 2 = 2
    2 4 / = 2 / 4 = 0.5
    So I guess 36 is right, thanks

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