Introduction

In this blog post, we will explore how to solve the LeetCode problem "2520" 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 num, return the number of digits in num that divide num. An integer val divides nums if nums % val == 0. Example 1: Input: num = 7 Output: 1 Explanation: 7 divides itself, hence the answer is 1. Example 2: Input: num = 121 Output: 2 Explanation: 121 is divisible by 1, but not 2. Since 1 occurs twice as a digit, we return 2. Example 3: Input: num = 1248 Output: 4 Explanation: 1248 is divisible by all of its digits, hence the answer is 4. Constraints: 1 <= num <= 109 num does not contain 0 as one of its digits.

Explanation

Here's the breakdown of the solution:

• Iterate through digits: Convert the number to a string and iterate through each digit.
• Check divisibility: For each digit, check if it divides the original number without any remainder using the modulo operator (%).

• Count divisible digits: Increment a counter for each digit that divides the original number.

• Runtime Complexity: O(log₁₀(num)), Storage Complexity: O(1)

Code

    def count_digits(num: int) -> int:
    """
    Given an integer num, return the number of digits in num that divide num.
    An integer val divides nums if nums % val == 0.

    Example 1:
    Input: num = 7
    Output: 1
    Explanation: 7 divides itself, hence the answer is 1.

    Example 2:
    Input: num = 121
    Output: 2
    Explanation: 121 is divisible by 1, but not 2. Since 1 occurs twice as a digit, we return 2.

    Example 3:
    Input: num = 1248
    Output: 4
    Explanation: 1248 is divisible by all of its digits, hence the answer is 4.

    Constraints:
    1 <= num <= 109
    num does not contain 0 as one of its digits.
    """
    count = 0
    num_str = str(num)
    for digit in num_str:
        digit_int = int(digit)
        if num % digit_int == 0:
            count += 1
    return count