Introduction

In this blog post, we will explore how to solve the LeetCode problem "1281" 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

Given an integer number n, return the difference between the product of its digits and the sum of its digits. Example 1: Input: n = 234 Output: 15 Explanation: Product of digits = 2 3 4 = 24 Sum of digits = 2 + 3 + 4 = 9 Result = 24 - 9 = 15 Example 2: Input: n = 4421 Output: 21 Explanation: Product of digits = 4 4 2 * 1 = 32 Sum of digits = 4 + 4 + 2 + 1 = 11 Result = 32 - 11 = 21 Constraints: 1 <= n <= 10^5

Explanation

Here's a breakdown of the approach and the Python code:

• Approach:

  • Iterate through the digits of the number.
  • Calculate the product and the sum of the digits in a single loop.
  • Return the difference between the product and the sum.

• Complexity:

  • Runtime Complexity: O(log n) - where n is the input number, as we iterate through the digits.
  • Storage Complexity: O(1) - constant extra space.

Code

    def subtractProductAndSum(n: int) -> int:
    """
    Given an integer number n, return the difference between the product of its digits and the sum of its digits.
    """
    product = 1
    sum_digits = 0
    num_str = str(n)

    for digit in num_str:
        digit_int = int(digit)
        product *= digit_int
        sum_digits += digit_int

    return product - sum_digits