Given an array of **unique** integers `salary`

where `salary[i]`

is the salary of the employee `i`

.

Return the average salary of employees excluding the minimum and maximum salary.

**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

**Example 3:**

**Input:** salary = [6000,5000,4000,3000,2000,1000]

**Output:** 3500.00000

**Example 4:**

**Input:** salary = [8000,9000,2000,3000,6000,1000]

**Output:** 4750.00000

Solutions:

**Time complexity**: O(n), traveling salary array list once

**Space complexity: **O(1), storing result into avgSalary variable.