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        riddles >> microsoft >> REMOVE PARENTHESES 
        
(Message started by: arvindwu on Nov 1^st, 2008, 1:56am)

Title: REMOVE PARENTHESES
Post by arvindwu on Nov 1^st, 2008, 1:56am

how to remove redundent parentheses

(A+B) = A+B
(A+(B*C) ) = A+B*C
((A+B)*C) = (A+B)*C
A/(B+C) = A/(B+C)

Title: Re: REMOVE PARENTHESES
Post by towr on Nov 1^st, 2008, 4:13am

Build a tree from the expression, and then use precedence rules:


C\P +  -  *  /
+:  _  r  lr lr
-:  _  r  lr lr
*:  _  _  _  r
/:  _  _  _  r

e.g. If the parent node (P) has the operator *, then a child (C) with operator + needs to be enveloped in parentheses when it's either the left (l) or right (r) child.
If the parent node (P) has the operator /, then a child (C) with operator * needs to be enveloped in parentheses only if it's the right (r) child, but not when it's the left (l).

Title: Re: REMOVE PARENTHESES
Post by towr on Apr 5^th, 2013, 6:21am

I'm getting the distinct impression you're just spamming... I can't remember any of your posts contributing anything, it's all "I agree", "thanks", "I didn't know that".

Title: Re: REMOVE PARENTHESES
Post by Grimbal on Apr 7^th, 2013, 7:09am

Me too. I even started to removed this kind of posts where there is no contribution to the subject.

PS: oops, I was cleaning up this kind of messages and I accidentally deleted the message you were commenting on.

For info, towr was replying to Mariko79 who just quoted towr's previous message and said something like "Thanks, buddy".