AcWing 数位DP相关问题 1085. 不要62

import sys
sys.stdin = open('data.txt', 'r')



def get_num(n):

    if n <= 0:
        return 1 # 统一把1算进答案里面，相减就抵消掉了

    arr = []
    val = n
    while val:
        arr.append(val % 10)
        val //= 10

    from functools import lru_cache
    @lru_cache(typed=False, maxsize=128000000)
    def dp(i, higher_val, all_higher_max):
        upper_bound = arr[i] if all_higher_max else 9
        cnt = 0
        for cur_val in range(upper_bound+1):
            if cur_val == 4:
                continue
            if higher_val == 6 and cur_val == 2:
                continue

            cnt += 1 if i == 0 else dp(i-1, cur_val, all_higher_max and cur_val == arr[i])
        return cnt

    return dp(len(arr)-1, 0, True)


while True:
    a, b = map(int, input().split())
    if a == 0 and b == 0:
        break

    print( get_num(b) - get_num(a-1) )