# Solving Leetcode Interviews in Seconds with AI: Mean of Array After Removing Some Elements


	# Introduction
	In this blog post, we will explore how to solve the LeetCode problem "1619" 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 array arr, return the mean of the remaining integers after removing the smallest 5% and the largest 5% of the elements. Answers within 10-5 of the actual answer will be considered accepted.   Example 1:  Input: arr = [1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3] Output: 2.00000 Explanation: After erasing the minimum and the maximum values of this array, all elements are equal to 2, so the mean is 2.  Example 2:  Input: arr = [6,2,7,5,1,2,0,3,10,2,5,0,5,5,0,8,7,6,8,0] Output: 4.00000  Example 3:  Input: arr = [6,0,7,0,7,5,7,8,3,4,0,7,8,1,6,8,1,1,2,4,8,1,9,5,4,3,8,5,10,8,6,6,1,0,6,10,8,2,3,4] Output: 4.77778    Constraints:  20 <= arr.length <= 1000 arr.length is a multiple of 20. 0 <= arr[i] <= 105  

	# Explanation
	Here's the solution:

*   **Sort the array:** Sorting allows us to easily identify and exclude the smallest and largest 5% of elements.
*   **Calculate trim indices:** Determine the indices corresponding to the 5th and 95th percentiles of the sorted array.
*   **Calculate the mean:** Sum the elements between the trim indices and divide by the number of elements included in the sum.

*   **Runtime Complexity:** O(n log n), where n is the length of the array (due to sorting). **Storage Complexity:** O(1) (in-place sort can be used, otherwise O(n) for creating a sorted copy)

	
	# Code
	```python
	def trim_mean(arr: list[int]) -> float:
    """
    Calculates the mean of the remaining integers after removing the smallest 5%
    and the largest 5% of the elements in an integer array.

    Args:
        arr (list[int]): The input integer array.

    Returns:
        float: The mean of the remaining integers after trimming.
    """

    n = len(arr)
    trim_percent = 0.05
    trim_count = int(n * trim_percent)

    arr.sort()  # Sort the array in ascending order

    trimmed_arr = arr[trim_count:n - trim_count]

    if not trimmed_arr:
        return 0.0  # Handle edge case where the array is too small after trimming

    return sum(trimmed_arr) / len(trimmed_arr)
	```