39. Combination Sum - LeetCode Solution

class Solution:
    def combinationSum(self, candidates: List[int], target: int) -> List[List[int]]:
        
        s = []
        nums = candidates


        def trav( ans, i, t):
            if ans == 0:
                s.append(t)
                return 1
            if ans < 0:
                return 0

            for j in range(i, len(nums), 1):
                trav(ans - nums[j], j, t + [nums[j]])


        trav(target, 0, [])
        return s