# LeetCode 7171-bit and 2-bit Characters

## LeetCode 717 1-bit and 2-bit Characters Problem

``````# 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.

# https://leetcode.com/problems/1-bit-and-2-bit-characters/solution/
class Solution:
def isOneBitCharacter(self, bits: List[int]) -> bool:
pos = 0
# Go through bits
while pos < len(bits) - 1:
# if 1, pos + 2; if 0, pos + 1
pos += bits[pos] + 1
return pos == len(bits) - 1

# def isOneBitCharacter(self, bits):
#     # From len - 2
#     pos = len(bits) - 2
#     # until encounter 0
#     while pos >= 0 and bits[pos] > 0:
#         pos -= 1
#     # check if second last zero is even
#     return (len(bits) - pos) % 2 == 0
``````

## List of all 1-bit and 2-bit Characters problems

Leetcode 717 1-bit and 2-bit Characters problem solution in python3 with explanation. This is the best place to expand your knowledge and get prepared for your next interview.

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.

Feedback is the most important part of any website.