22. Generate Parentheses
Содержание
Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.
Example 1:
Input: n = 3
Output: ["((()))","(()())","(())()","()(())","()()()"]
Example 2:
Input: n = 1
Output: ["()"]
Prerequirements
First accepted
Idea:
class Solution:
def generateParenthesis(self, n):
res = []
def dfs(l: int, r: int, s: str) -> None:
if l == 0 and r == 0:
res.append(s)
if l > 0:
dfs(l - 1, r, s + '(')
if l < r:
dfs(l, r - 1, s + ')')
dfs(n, n, '')
return res
