Parentheses Pairs

2021-09-13.py

question = """
Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.

Example:

$ formParens(1)
$ ["()"]

$ formParens(3)
$ ["((()))","(()())","(())()","()(())","()()()"]

"""

def formParens(n):
    paren_array_keys = {}
    paren_array = []
    if n == 1:
        return [ "()" ]
    if n > 1:
        lower_set = formParens(n - 1)
        for set in lower_set:
            prepend_set = '()' + set
            append_set = set + '()'
            encase_set = '(' + set + ')'

            paren_array_keys[prepend_set] = 1
            paren_array_keys[append_set] = 1
            paren_array_keys[encase_set] = 1
    for key in paren_array_keys.keys():
        paren_array.append(key)
    return paren_array

print(formParens(1))

print(formParens(3))

Thank you very much

Thanks to you!

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