22. Generate Parentheses - LeetCode Solution

class Solution:
    def generateParenthesis(self, n: int) -> List[str]:
        
        a = []
        
        
        actual = n
        def trav(n, b, i, j):
            if len(b) == 2*n:
                a.append(b)
                return 
            
            for k in range(i, n, 1):
                trav(n, b+"(", k+1, j)
            
            for l in range(j, i, 1):
                trav(n, b+")", i, l+1)
                
                

        
        trav(n, "", 0, 0)
        
        return a