From d95d2b93e89e2dce1db7a17f15b8ec293ed4be96 Mon Sep 17 00:00:00 2001
From: shellhub <shellhub.me@gmail.com>
Date: Thu, 6 May 2021 17:44:44 +0800
Subject: [PATCH 1/2] reformat merge sort

---
 Sorts/MergeSort.java | 55 +++++++++++++++++++++-----------------------
 1 file changed, 26 insertions(+), 29 deletions(-)

diff --git a/Sorts/MergeSort.java b/Sorts/MergeSort.java
index dfd350afb283..83deb176e108 100644
--- a/Sorts/MergeSort.java
+++ b/Sorts/MergeSort.java
@@ -1,22 +1,17 @@
 package Sorts;
 
-import static Sorts.SortUtils.print;
-
 /**
- * This method implements the Generic Merge Sort
- *
- * @author Varun Upadhyay (https://github.com/varunu28)
- * @author Podshivalov Nikita (https://github.com/nikitap492)
+ * Generic merge sort algorithm.
  * @see SortAlgorithm
  */
 class MergeSort implements SortAlgorithm {
 
   /**
-   * This method implements the Generic Merge Sort
+   * Generic merge sort algorithm implements.
    *
-   * @param unsorted the array which should be sorted
-   * @param <T> Comparable class
-   * @return sorted array
+   * @param unsorted the array which should be sorted.
+   * @param <T> Comparable class.
+   * @return sorted array.
    */
   @Override
   public <T extends Comparable<T>> T[] sort(T[] unsorted) {
@@ -25,13 +20,13 @@ public <T extends Comparable<T>> T[] sort(T[] unsorted) {
   }
 
   /**
-   * @param arr The array to be sorted
-   * @param left The first index of the array
-   * @param right The last index of the array Recursively sorts the array in increasing order
+   * @param arr the array to be sorted.
+   * @param left the first index of the array.
+   * @param right the last index of the array.
    */
   private static <T extends Comparable<T>> void doSort(T[] arr, int left, int right) {
     if (left < right) {
-      int mid = left + (right - left) / 2;
+      int mid = (left + right) >>> 1;
       doSort(arr, left, mid);
       doSort(arr, mid + 1, right);
       merge(arr, left, mid, right);
@@ -39,15 +34,16 @@ private static <T extends Comparable<T>> void doSort(T[] arr, int left, int righ
   }
 
   /**
-   * This method implements the merge step of the merge sort
+   * Merges two parts of an array.
    *
-   * @param arr The array to be sorted
-   * @param left The first index of the array
-   * @param mid The middle index of the array
-   * @param right The last index of the array merges two parts of an array in increasing order
+   * @param arr the array to be merged.
+   * @param left the first index of the array.
+   * @param mid the middle index of the array.
+   * @param right the last index of the array merges two parts of an array in increasing order.
    */
   private static <T extends Comparable<T>> void merge(T[] arr, int left, int mid, int right) {
     int length = right - left + 1;
+    @SuppressWarnings("unchecked")
     T[] temp = (T[]) new Comparable[length];
     int i = left;
     int j = mid + 1;
@@ -72,21 +68,22 @@ private static <T extends Comparable<T>> void merge(T[] arr, int left, int mid,
     System.arraycopy(temp, 0, arr, left, length);
   }
 
-  // Driver program
+  /**
+   * Driver code
+   */
   public static void main(String[] args) {
+    MergeSort mergeSort = new MergeSort();
 
-    // Integer Input
     Integer[] arr = {4, 23, 6, 78, 1, 54, 231, 9, 12};
-    MergeSort mergeSort = new MergeSort();
     mergeSort.sort(arr);
+    for (int i = 0; i < arr.length - 1; ++i) {
+      assert arr[i] <= arr[i + 1];
+    }
 
-    // Output => 1	   4  	 6	9	12	23	54	78	231
-    print(arr);
-
-    // String Inpu
     String[] stringArray = {"c", "a", "e", "b", "d"};
     mergeSort.sort(stringArray);
-    // Output => a	b	c	d	e
-    print(stringArray);
+    for (int i = 0; i < stringArray.length - 1; ++i) {
+      assert arr[i].compareTo(arr[i + 1]) <= 0;
+    }
   }
-}
+}
\ No newline at end of file

From 9cc36e02c2aac685c115c09cee37bf515851e913 Mon Sep 17 00:00:00 2001
From: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Date: Thu, 6 May 2021 09:45:51 +0000
Subject: [PATCH 2/2] Formatted with Google Java Formatter

---
 Sorts/MergeSort.java | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/Sorts/MergeSort.java b/Sorts/MergeSort.java
index 83deb176e108..57892bc6bc46 100644
--- a/Sorts/MergeSort.java
+++ b/Sorts/MergeSort.java
@@ -2,6 +2,7 @@
 
 /**
  * Generic merge sort algorithm.
+ *
  * @see SortAlgorithm
  */
 class MergeSort implements SortAlgorithm {
@@ -68,9 +69,7 @@ private static <T extends Comparable<T>> void merge(T[] arr, int left, int mid,
     System.arraycopy(temp, 0, arr, left, length);
   }
 
-  /**
-   * Driver code
-   */
+  /** Driver code */
   public static void main(String[] args) {
     MergeSort mergeSort = new MergeSort();
 
@@ -86,4 +85,4 @@ public static void main(String[] args) {
       assert arr[i].compareTo(arr[i + 1]) <= 0;
     }
   }
-}
\ No newline at end of file
+}