[leetCode] 1619. Mean of Array After Removing Some Elements (Python)

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

Example 4:

Input: arr = [9,7,8,7,7,8,4,4,6,8,8,7,6,8,8,9,2,6,0,0,1,10,8,6,3,3,5,1,10,9,0,7,10,0,10,4,1,10,6,9,3,6,0,0,2,7,0,6,7,2,9,7,7,3,0,1,6,1,10,3]
Output: 5.27778

Example 5:

Input: arr = [4,8,4,10,0,7,1,3,7,8,8,3,4,1,6,2,1,1,8,0,9,8,0,3,9,10,3,10,1,10,7,3,2,1,4,9,10,7,6,4,0,8,5,1,2,1,6,2,5,0,7,10,9,10,3,7,10,5,8,5,7,6,7,6,10,9,5,10,5,5,7,2,10,7,7,8,2,0,1,1]
Output: 5.29167

 

Constraints:

• 20 <= arr.length <= 1000
• arr.length is a multiple of 20.
• 0 <= arr[i] <= 105

Solution

class Solution:
    def trimMean(self, arr: List[int]) -> float:
        sorted_arr = sorted(arr)
        
        five_percent = int(len(arr)*0.05)
        
        arr_len = len(arr)
        
        answer_arr = sorted_arr[five_percent:arr_len-five_percent]
        
        return sum(answer_arr) / len(answer_arr)

Solution 해설

문제는 입력받은 리스트 중에서 작은값 5% 큰값 5%를 제외한 모든 값의 평균을 구하는 문제입니다.

따라서 five_percent 변수에 전체 리스트 길이의 5%를 구하고

arr을 정렬한 다음 five_percent를 활용하여 작은값 5% 큰값 5%를 제외한 리스트를 만들고 평균을 구합니다.

SOMJANG/CODINGTEST_PRACTICE