Combination Sum III

class Solution:
    def combinationSum3(self, k: int, n: int) -> List[List[int]]:
        combos = []
        currCombo = []

        def solve(num, rem, sz):
            if sz == k and rem == 0:
                combos.append(currCombo[:])
                return

            if num > 9 or rem < num or sz >= k:
                return

            solve(num+1, rem, sz)

            currCombo.append(num)
            solve(num+1, rem-num, sz+1)
            currCombo.pop()

        solve(1, n, 0)
        return combos