题解 | #括号生成#

#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param n int整型 
# @return string字符串一维数组
#
class Solution:
    def generateParenthesis(self , n: int) -> List[str]:
        # write code here

        import functools
        @functools.cache
        def dfs(n):
            if n<=0: return [""]
            res = []
            for i in range(n):
                for i0 in dfs(i):
                    for i1 in dfs(n-(i+1)):
                        res.append("("+i0+")"+i1)
            return res
        
        return dfs(n)