# Solving Leetcode Interviews in Seconds with AI: Harshad Number


	# Introduction
	In this blog post, we will explore how to solve the LeetCode problem "3099" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like [Chatmagic](https://www.chatmagic.app), 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
	> An integer divisible by the sum of its digits is said to be a Harshad number. You are given an integer x. Return the sum of the digits of x if x is a Harshad number, otherwise, return -1.   Example 1:  Input: x = 18 Output: 9 Explanation: The sum of digits of x is 9. 18 is divisible by 9. So 18 is a Harshad number and the answer is 9.  Example 2:  Input: x = 23 Output: -1 Explanation: The sum of digits of x is 5. 23 is not divisible by 5. So 23 is not a Harshad number and the answer is -1.    Constraints:  1 <= x <= 100  

	# Explanation
	Here's a breakdown of the solution:

*   **Calculate Digit Sum:** Iterate through the digits of the input number `x` and compute their sum.
*   **Harshad Number Check:** Verify if the original number `x` is divisible by the calculated digit sum.
*   **Return Value:** If divisible, return the digit sum; otherwise, return -1.

*   **Runtime Complexity:** O(log x) (due to digit extraction), **Storage Complexity:** O(1)

	
	# Code
	```python
	def solve():
    x = int(input())
    
    sum_digits = 0
    temp = x
    while temp > 0:
        sum_digits += temp % 10
        temp //= 10
    
    if sum_digits == 0:
      print(-1)
      return
    
    if x % sum_digits == 0:
        print(sum_digits)
    else:
        print(-1)

solve()
	```