class Solution: def generateParenthesis(self , n: int) -> List[str]: # write code here rs = [] def go(l,r,temp): if l>n or r>n or r>l: return if l == n and r == n: rs.append(temp) else: go(l+1, r, temp+'(') go(l, r+1, temp+')') go(0,0,'') return rs