Introduction

In this blog post, we will explore how to solve the LeetCode problem "66" 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

You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0's. Increment the large integer by one and return the resulting array of digits. Example 1: Input: digits = [1,2,3] Output: [1,2,4] Explanation: The array represents the integer 123. Incrementing by one gives 123 + 1 = 124. Thus, the result should be [1,2,4]. Example 2: Input: digits = [4,3,2,1] Output: [4,3,2,2] Explanation: The array represents the integer 4321. Incrementing by one gives 4321 + 1 = 4322. Thus, the result should be [4,3,2,2]. Example 3: Input: digits = [9] Output: [1,0] Explanation: The array represents the integer 9. Incrementing by one gives 9 + 1 = 10. Thus, the result should be [1,0]. Constraints: 1 <= digits.length <= 100 0 <= digits[i] <= 9 digits does not contain any leading 0's.

Explanation

• Iterate from right to left: Starting from the least significant digit, increment it by one.
  • Handle carry: If a digit becomes 10, set it to 0 and carry over 1 to the next digit.
  • Handle overflow: If there's a carry after incrementing the most significant digit, insert a new digit '1' at the beginning of the array.

• Runtime Complexity: O(n), where n is the number of digits. Storage Complexity: O(1) in most cases, O(n) in the worst case (when a new digit needs to be inserted at the beginning).

Code

    def plusOne(digits: list[int]) -> list[int]:
    """
    Given a non-empty array of decimal digits representing a non-negative integer, increment one to the integer.

    The digits are stored such that the most significant digit is at the head of the list, and each element in the array contains a single digit.

    You may assume the integer does not contain any leading zero, except the number 0 itself.

    Args:
        digits: A list of integers representing the digits of a non-negative integer.

    Returns:
        A list of integers representing the digits of the incremented integer.
    """
    n = len(digits)
    for i in range(n - 1, -1, -1):
        if digits[i] < 9:
            digits[i] += 1
            return digits
        digits[i] = 0

    # If we reach here, it means all digits were 9
    return [1] + digits