1984. Minimum Difference Between Highest and Lowest of K Scores

Problem

You are given a 0-indexed integer array nums, where nums[i] represents the score of the ith student. You are also given an integer k.

Pick the scores of any k students from the array so that the difference between the highest and the lowest of the k scores is minimized.

Return **the *minimum* possible difference**.

  Example 1:

Input: nums = [90], k = 1
Output: 0
Explanation: There is one way to pick score(s) of one student:
- [90]. The difference between the highest and lowest score is 90 - 90 = 0.
The minimum possible difference is 0.

Example 2:

Input: nums = [9,4,1,7], k = 2
Output: 2
Explanation: There are six ways to pick score(s) of two students:
- [9,4,1,7]. The difference between the highest and lowest score is 9 - 4 = 5.
- [9,4,1,7]. The difference between the highest and lowest score is 9 - 1 = 8.
- [9,4,1,7]. The difference between the highest and lowest score is 9 - 7 = 2.
- [9,4,1,7]. The difference between the highest and lowest score is 4 - 1 = 3.
- [9,4,1,7]. The difference between the highest and lowest score is 7 - 4 = 3.
- [9,4,1,7]. The difference between the highest and lowest score is 7 - 1 = 6.
The minimum possible difference is 2.

  Constraints:

• 1 <= k <= nums.length <= 1000

• 0 <= nums[i] <= 10^5

Solution (Java)

class Solution {
    public int minimumDifference(int[] nums, int k) {
        Arrays.sort(nums);
        int minDiff = nums[nums.length - 1];
        for (int i = 0; i <= nums.length - k; i++) {
            minDiff = Math.min(minDiff, nums[i + k - 1] - nums[i]);
        }
        return minDiff;
    }
}

Explain:

nope.

Complexity:

• Time complexity : O(n).
• Space complexity : O(n).