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1619. Mean of Array After Removing Some Elements

Difficulty Topics

Description

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

Solution

mean-of-array-after-removing-some-elements.py
class Solution:
    def trimMean(self, arr: List[int]) -> float:
        n = len(arr)
        k = int(len(arr)*0.05)

        arr.sort()
        count = res = 0

        for i in range(k,n-k):
            res += 1
            count += arr[i]

        return count / res