题目
Return all non-negative integers of length N such that the absolute difference between every two consecutive digits is K.
Note that every number in the answer must not have leading zeros except for the number 0 itself. For example, 01 has one leading zero and is invalid, but 0 is valid.
You may return the answer in any order.
解题思路
BFS，先确定第一位为0-9，然后后面可以是个位数+K或者-K，但是要在0到9之间，如果K=0，要去重
代码
class Solution:
def numsSameConsecDiff(self, N: int, K: int) -> List[int]:
if N == 1:
return range(10)
q = range(1, 10)
for i in range(N - 1):
tmp = []
for n in q:
for d in set([n % 10 + K, n % 10 - K]):
if 0 <= d < 10:
tmp.append(n * 10 + d)
q = tmp
return q
