题目
An integer has sequential digits if and only if each digit in the number is one more than the previous digit.
Return a sorted list of all the integers in the range [low, high] inclusive that have sequential digits.
解题思路
如果一个数符合条件，一定是“123456789”的一个连续子串，先枚举这个数的位数，再枚举长度，如果当前的数大于high，就可以停止了
代码
class Solution:
def sequentialDigits(self, low: int, high: int) -> List[int]:
seq = '123456789'
res = []
for l in range(1, 10):
for i in range(len(seq) - l + 1):
num = int(seq[i: i + l])
if num > high:
return res
if num >= low:
res.append(num)
return res
