1984.minimumDifference.go

/*
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] <= 105

Seen this question in a real interview before?
1/5
Yes
No
Accepted
99.6K
Submissions
171.1K
Acceptance Rate
58.2%
Topics
Array
Sliding Window
Sorting
Companies
0 - 6 months
Tinkoff
3
Google
2
6 months ago
Meta
3
Amazon
2
Hint 1
For the difference between the highest and lowest element to be minimized, the k chosen scores need to be as close to each other as possible.
Hint 2
What if the array was sorted?
Hint 3
After sorting the scores, any contiguous k scores are as close to each other as possible.
Hint 4
Apply a sliding window solution to iterate over each contiguous k scores, and find the minimum of the differences of all windows.
Similar Questions
Array Partition
*/

package main

import (
	"fmt"
	"math"
	"sort"
)

func minimumDifference(nums []int, k int) int {
	// sort the arr in place
	sort.Ints(nums)

	// sliding window size k
	// pick l, r in this window
	// find the minimum differences
	l, r := 0, k-1
	res := math.MaxInt

	for r < len(nums) {
		// r always > l since it's sorted
		res = int(math.Min(float64(res), float64(nums[r]-nums[l])))
		l++
		r++
	}

	return res
}

func main() {
	arr := []int{9, 4, 1, 7}
	fmt.Println(minimumDifference(arr, 2)) // 2
}