LeetCode in Kotlin

2465. Number of Distinct Averages

Easy

You are given a 0-indexed integer array nums of even length.

As long as nums is not empty, you must repetitively:

The average of two numbers a and b is (a + b) / 2.

Return the number of distinct averages calculated using the above process.

Note that when there is a tie for a minimum or maximum number, any can be removed.

Example 1:

Input: nums = [4,1,4,0,3,5]

Output: 2

Explanation:

  1. Remove 0 and 5, and the average is (0 + 5) / 2 = 2.5. Now, nums = [4,1,4,3].

  2. Remove 1 and 4. The average is (1 + 4) / 2 = 2.5, and nums = [4,3].

  3. Remove 3 and 4, and the average is (3 + 4) / 2 = 3.5.

Since there are 2 distinct numbers among 2.5, 2.5, and 3.5, we return 2.

Example 2:

Input: nums = [1,100]

Output: 1

Explanation:

There is only one average to be calculated after removing 1 and 100, so we return 1.

Constraints:

Solution

class Solution {
    fun distinctAverages(nums: IntArray): Int {
        nums.sort()
        val set: MutableSet<Int> = HashSet()
        var l = 0
        var r = nums.size - 1
        while (l < r) {
            set.add(nums[l++] + nums[r--])
        }
        return set.size
    }
}