Roof Length - JAVA

import java.util.*;

public class Test {

    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {

        int n = sc.nextInt();
        int k = sc.nextInt();
        int arr[] = new int[n];

        for(int i = 0; i < n; i++)
            arr[i] = sc.nextInt();

        int res = roofLength(n, k, arr);
        System.out.println(res);
    }

    public static int roofLength(int n, int k, int[] cars) {
        Arrays.sort(cars);
        int res = cars[k-1] - cars[0] + 1;

        for(int i=1 ; i < n - k + 1; i++) {
            res = Math.min(res, cars[k-1+i] - cars[i] + 1);
        }

        return res;
    }
}