Create MergeSort.java

Author: Eggy115

Diff for: MergeSort.java

@@ -0,0 +1,26 @@
+import java.util.Arrays;
+
+public class MergeSort {
+    public static void main(String[] args) {
+        int[] arr = { 38, 27, 43, 3, 9, 82, 10 };
+        System.out.println("Unsorted array: " + Arrays.toString(arr));
+        mergeSort(arr, 0, arr.length - 1);
+        System.out.println("Sorted array: " + Arrays.toString(arr));
+    }
+    
+    public static void mergeSort(int[] arr, int left, int right) {
+        if (left < right) {
+            int mid = (left + right) / 2;
+            mergeSort(arr, left, mid);
+            mergeSort(arr, mid + 1, right);
+            merge(arr, left, mid, right);
+        }
+    }
+    
+    public static void merge(int[] arr, int left, int mid, int right) {
+        int[] temp = new int[right - left + 1];
+        int i = left, j = mid + 1, k = 0;
+        while (i <= mid && j <= right) {
+            if (arr[i] <= arr[j]) {
+                temp[k++] = arr[i++];
+            }