Time:Time: Space:Space: C++ class Solution: def kMirror(self, k: int, n: int) -> int: ans = 0 A = ['0'] def nextKMirror(A: List[chr]) -> List[chr]: for i in range(len(A) // 2, len(A)): nextNum = int(A[i]) + 1 if nextNum < k: A[i] = str(nextNum) A[~i] = str(nextNum) for j in range(len(A) // 2, i): A[j] = '0' A[~j] = '0' return A return ['1'] + ['0'] * (len(A) - 1) + ['1'] for _ in range(n): while True: A = nextKMirror(A) num = int(''.join(A), k) if str(num)[::-1] == str(num): break ans += num return ans