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13. reverseInParentheses

Dududoo on Python_codesignal


Task

Write a function that reverses characters in (possibly nested) parentheses in the input string.

Input strings will always be well-formed with matching ()s.

Example

  • For inputString = "(bar)", the output should be
    reverseInParentheses(inputString) = "rab";

  • For inputString = "foo(bar)baz", the output should be
    reverseInParentheses(inputString) = "foorabbaz";

  • For inputString = "foo(bar)baz(blim)", the output should be
    reverseInParentheses(inputString) = "foorabbazmilb";

  • For inputString = "foo(bar(baz))blim", the output should be
    reverseInParentheses(inputString) = "foobazrabblim".
    Because "foo(bar(baz))blim" becomes "foo(barzab)blim" and then "foobazrabblim".

Input/Output

  • [execution time limit]
    4 seconds (py3)

  • [input] string inputString
    A string consisting of lowercase English letters and the characters ( and ). It is guaranteed that all parentheses in inputString form a regular bracket sequence.
    Guaranteed constraints: 0 ≤ inputString.length ≤ 50.

  • [output] string
    Return inputString, with all the characters that were in parentheses reversed.

My Solution

def reverseInParentheses(inputString):
    i = 0
    rev = ''
    while i < len(inputString):
        if inputString[i] == '(':
            j, revPar = reverseInParentheses(inputString[i + 1:])
            rev += revPar
            i += j + 2
        elif inputString[i] == ')':
            return i, rev[::-1]
        else:
            rev += inputString[i]
            i += 1
    return rev