题目:原题链接(中等)
标签:回溯算法
解法 | 时间复杂度 | 空间复杂度 | 执行用时 |
Ans 1 (Python) | O ( 2 N ) | O ( 2 N ) | 48ms (39.53%) |
Ans 2 (Python) | |||
Ans 3 (Python) |
解法一:
class Solution:
def generateParenthesis(self, n: int, left: int = 0) -> List[str]:
self.now = []
self.ans = []
def count(l, r):
if l == r:
self.now.append("(")
count(l + 1, r)
self.now.pop()
elif l == n:
self.ans.append("".join(self.now + [")"] * (l - r)))
else:
self.now.append("(")
count(l + 1, r)
self.now.pop()
self.now.append(")")
count(l, r + 1)
self.now.pop()
count(l=0, r=0)
return self.ans