717. 1-bit and 2-bit Characters

# 717. 1-bit and 2-bit Characters

## 刷题内容

We have two special characters. The first character can be represented by one bit 0. The second character can be represented by two bits (10 or 11).

Now given a string represented by several bits. Return whether the last character must be a one-bit character or not. The given string will always end with a zero.

Example 1:
Input:
bits = [1, 0, 0]
Output: True
Explanation:
The only way to decode it is two-bit character and one-bit character. So the last character is one-bit character.
Example 2:
Input:
bits = [1, 1, 1, 0]
Output: False
Explanation:
The only way to decode it is two-bit character and two-bit character. So the last character is NOT one-bit character.
Note:

1 <= len(bits) <= 1000.
bits[i] is always 0 or 1.

- 时间复杂度: O(N)- 空间复杂度: O(1)

`python
class Solution:
def isOneBitCharacter(self, bits: List[int]) -> bool:
def helper(bits): # 返回bits是否可以成功decode
if not bits:
return True
if len(bits) == 1:
if bits[0] == 0: