One file is to implement: MySort.java. In this file, the students must provide the following public interface:

public static void insertSort(int [] arr); public static void selectSort(int [] arr); public static void quickSort(int [] arr); public static void mergeSort(int [] arr);

The quick sort and merge sort must be implemented by using recursive thinking. So the students may provide the following private static methods: // merge method // merge two sorted portions of given array arr, namely, from start to middle // and from middle + 1 to end into one sorted portion, namely, from start to end private static void merge(int [] arr, int start, int middle, int end); // merge sort recursive version // sort the portion of giving array arr, from begin to end private static void mergeSortRecursive(int [] arr, int begin, int end);

// find pivot point for quick sort private static int pivot(int [] arr, int begin, int end);

// quick sort recursive version // sort the portion of giving array arr, from begin to end private static void quickSortRecursive(int [] arr, int begin, int end);

The student need to have and only have the above public and private static methods in his/her implementation of MySort class