# Solving Leetcode Interviews in Seconds with AI: Find Three Consecutive Integers That Sum to a Given Number


	# Introduction
	In this blog post, we will explore how to solve the LeetCode problem "2177" 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
	> Given an integer num, return three consecutive integers (as a sorted array) that sum to num. If num cannot be expressed as the sum of three consecutive integers, return an empty array.   Example 1:  Input: num = 33 Output: [10,11,12] Explanation: 33 can be expressed as 10 + 11 + 12 = 33. 10, 11, 12 are 3 consecutive integers, so we return [10, 11, 12].  Example 2:  Input: num = 4 Output: [] Explanation: There is no way to express 4 as the sum of 3 consecutive integers.    Constraints:  0 <= num <= 1015  

	# Explanation
	Here's the breakdown of the solution:

*   **Mathematical Approach:** The sum of three consecutive integers `x`, `x+1`, and `x+2` is `3x + 3`. If `num` is the sum, then `3x + 3 = num`, so `x = (num - 3) / 3`. If `x` is an integer, we have found our three consecutive integers.

*   **Integer Check:** We must ensure that the calculated value of `x` is an integer. We can check this by verifying that `(num - 3)` is divisible by 3.

*   **Array Construction:** If `x` is an integer, we construct the array `[x, x+1, x+2]` and return it. Otherwise, we return an empty array.

*   **Complexity:** O(1) runtime, O(1) storage.

	
	# Code
	```python
	def sum_of_three(num: int) -> list[int]:
    """
    Given an integer num, return three consecutive integers (as a sorted array) that sum to num.
    If num cannot be expressed as the sum of three consecutive integers, return an empty array.

    For example:
    sum_of_three(33) == [10, 11, 12]
    sum_of_three(4) == []
    """
    if (num - 3) % 3 == 0:
        x = (num - 3) // 3
        return [x, x + 1, x + 2]
    else:
        return []
	```