class Solution: def numsSameConsecDiff(self, n: int, k: int) -> List[int]: def backtrack(): if len(current) == n: if current[0] != 0: result.append(''.join([str(d) for d in current])) return for i in range(10): if current and abs(i - current[-1]) != k: continue current.append(i) backtrack() current.pop() result = [] current = [] backtrack() return result