标签：bin set div app function help res func The
Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.
For example, given n = 3, a solution set is:
[ "((()))", "(()())", "(())()", "()(())", "()()()" ]
Time: O(2^N)
Space: O(N)
1 class Solution: 2 def generateParenthesis(self, n: int) -> List[str]: 3 res = [] 4 self.helper(0, 0, n, ‘‘, res) 5 return res 6 7 def helper(self, left, right, n, word, res): 8 if left == n and right == n: 9 res.append(word) 10 if left < n: 11 word += ‘(‘ 12 self.helper(left + 1, right, n, word, res) 13 word = word[:-1] 14 if left > right: 15 word += ‘)‘ 16 self.helper(left, right + 1, n, word, res) 17 word = word[:-1]
标签：bin set div app function help res func The
原文地址：https://www.cnblogs.com/xuanlu/p/11566769.html
