Introduction

In this blog post, we will explore how to solve the LeetCode problem "717" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like Chatmagic, we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

Problem Statement

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). Given a binary array bits that ends with 0, return true if the last character must be a one-bit character. 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. Constraints: 1 <= bits.length <= 1000 bits[i] is either 0 or 1.

Explanation

Here's an efficient solution to determine if the last character in a binary array is a one-bit character:

• Iterate from the beginning: Traverse the array from left to right, simulating the decoding process.
• Check for two-bit characters: If we encounter a '1', it indicates a two-bit character, so we advance the index by two. If we encounter a '0', it indicates a one-bit character, so we advance by one.

• Determine the last character: If the loop finishes at the second to last position, it means that the last bit must be a 1-bit character, because the last character must be 0, according to the problem definition.

• Runtime Complexity: O(n), where n is the length of the input array.

• Storage Complexity: O(1) - constant extra space.

Code

    def isOneBitCharacter(bits):
    """
    Determines if the last character in a binary array is a one-bit character.

    Args:
        bits: A list of integers representing the binary array.

    Returns:
        True if the last character is a one-bit character, False otherwise.
    """
    i = 0
    n = len(bits)
    while i < n - 1:
        if bits[i] == 1:
            i += 2
        else:
            i += 1
    return i == n - 1