Using Java remove unbalanced/unpartnered parenthesis

Question

I want to remove all the "unpartnered" or unpaired parenthesises from a string.

exampleStr = back-pay) zyzhk1219(17) zyzhk1329 zyzhk1595(15) zyzhk1988 zyzhk2004 zyzhk2131) jswioj((testsjkldf

The expected "parenthesis balanced" string should be

back-pay zyzhk1219(17) zyzhk1329 zyzhk1595(15) zyzhk1988 zyzhk2004 zyzhk2131 jswiojtestsjkldf

I saw some ruby based solution on stackoverflow. But, couldn't find one I can use in java.

Answer 1

How it might be done in pseudo-code:

initialize parenLevel = 0
for each character in string
    if char is ( increment parenLevel
    if char is )
        if parenLevel = 0, remove bad paren
        else, decrement parenLevel
next

initialize parenLevel = 0
for each character in string in reverse
    if char is ) increment parenLevel
    if char is (
        if parenLevel = 0, remove bad paren
        else, decrement parenLevel
next

How it might be implemented in practice: http://ideone.com/K3s0X

Sample result:

back-pay zyzhk1219(17) zyzhk1329 zyzhk1595(15) zyzhk1988 zyzhk2004 zyzhk2131 jswiojtestsjkldf