2148. Count Elements With Strictly Smaller and Greater Elements

Given an integer array nums, return the number of elements that have both a strictly smaller and a strictly greater element appear in nums.

Example 1:

Input: nums = [11,7,2,15]
Output: 2
Explanation: The element 7 has the element 2 strictly smaller than it and the element 11 strictly greater than it.
Element 11 has element 7 strictly smaller than it and element 15 strictly greater than it.
In total there are 2 elements having both a strictly smaller and a strictly greater element appear in nums.

Example 2:

Input: nums = [-3,3,3,90]
Output: 2
Explanation: The element 3 has the element -3 strictly smaller than it and the element 90 strictly greater than it.
Since there are two elements with the value 3, in total there are 2 elements having both a strictly smaller and a strictly greater element appear in nums.

Solution:

class Solution {
    public int countElements(int[] nums) {
        Arrays.sort(nums);
        int k = 0;
        for (int i = 1; i < nums.length; i++){
            if (nums[i] > nums[0] && nums[i] < nums[nums.length - 1]){
                k++;
            }
        }
        return k;

    }
}

// TC: O(nlogn)
// SC: O(1) - O(n)