Average Salary Excluding the Minimum and Maximum Salary

Problem Statement

In this challenge, you are tasked with calculating the average salary of employees, where you've given an array called salary containing the salary figures of each individual. Each number in the array is distinct, representing the unique salary of each employee. The challenge here is to compute the average salary while excluding both the highest and the lowest salaries from the computation. This task must ensure accuracy close to 10^-5 of the actual average for valid results.

Examples

Example 1

Input:

salary = [4000,3000,1000,2000]

Output:

2500.00000

Explanation:

Minimum salary and maximum salary are 1000 and 4000 respectively.
Average salary excluding minimum and maximum salary is (2000+3000) / 2 = 2500

Example 2

Input:

salary = [1000,2000,3000]

Output:

2000.00000

Explanation:

Minimum salary and maximum salary are 1000 and 3000 respectively.
Average salary excluding minimum and maximum salary is (2000) / 1 = 2000

Constraints

• 3 <= salary.length <= 100
• 1000 <= salary[i] <= 106
• All the integers of salary are unique.

Approach and Intuition

1. Identify and Exclude Minimum and Maximum Salaries:

   • First, determine the minimum and maximum salary values from the array since these are to be excluded from the calculation of the average. Python functions min() and max() can be effective here.

2. Average the Remaining Salaries:

   • After identifying and excluding the smallest and largest salaries, the next step involves summing up the remaining salaries. Python's sum() function can be utilized for calculating the total sum of the array.
   • Count the elements that are left after removing the minimum and maximum salaries.

3. Calculate the Average:

   • Finally, divide the summed total of remaining salaries by the count of these salaries to get the average.
   • Return or print the computed average with appropriate floating-point precision, as per the problem's requirement of maintaining accuracy within 10^-5.

Example Intuition from Provided Examples:

• For salary = [4000, 3000, 1000, 2000], exclude 1000 (min) and 4000 (max). The remaining salaries are 2000 and 3000. Their sum is 5000 and there are two elements, leading to an average of 2500.
• In the case of salary = [1000, 2000, 3000], 1000 and 3000 are excluded, and we're left with just 2000. So, the average is 2000 since it's the only element left.

Constraints:

• The number of employees (size of the given list) is at least three but not more than a hundred, ensuring there is always at least one salary to average out after removing the minimum and maximum.
• Salaries are significant numerical values ranging from 1000 to one million, which might require attention to numerical precision during the computation.
• The uniqueness of each salary simplifies the removal of the minimum and maximum values, as there will be no duplicates of these values to handle.

Solutions

class Solution {
public:
    double calculateAverage(vector<int>& salaryData) {
        int lowestSalary = INT_MAX;
        int highestSalary = INT_MIN;
        int totalSum = 0;
        
        for (int salary : salaryData) {
            totalSum += salary;
            lowestSalary = min(lowestSalary, salary);
            highestSalary = max(highestSalary, salary);
        }
        
        return (double)(totalSum - lowestSalary - highestSalary) / (double)(salaryData.size() - 2);
    }
};

class Solution {
    public double computeAverage(int[] wages) {
        int minimum = Integer.MAX_VALUE;
        int maximum = Integer.MIN_VALUE;
        int total = 0;

        for (int wage : wages) {
            total += wage;
            minimum = Math.min(minimum, wage);
            maximum = Math.max(maximum, wage);
        }

        return (double)(total - minimum - maximum) / (double)(wages.length - 2);
    }
}