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: ["()"]
Constraints:
-
1 <= n <= 8
SOLUTION:
class Solution:
def generate(self, s, ctr, rem, ans):
if rem == 0 and ctr == 0:
ans.add(s)
if rem > 0 and ctr >= 0:
if ctr < rem:
self.generate(s + '(', ctr + 1, rem - 1, ans)
if ctr > 0:
self.generate(s + ')', ctr - 1, rem - 1, ans)
def generateParenthesis(self, n: int) -> List[str]:
ans = set()
self.generate("", 0, 2 * n, ans)
return list(ans)
Top comments (0)