Merge and Quick sort

src/intermediate/MergeSort.java

@@ -0,0 +1,56 @@
+package intermediate;
+
+import java.util.Arrays;
+
+public class MergeSort {
+    public static void main(String[] args) {
+        int[] nums = {5, 4, 3, 2, 1};
+        System.out.println("Before: " + Arrays.toString(nums));
+        nums = mergeSort(nums);
+        System.out.println("After: " + Arrays.toString(nums));
+    }
+
+
+    static int[] mergeSort(int[] nums) {
+
+        if (nums.length == 1)
+            return nums;
+
+        int middle = nums.length / 2;
+        int[] left = mergeSort(Arrays.copyOfRange(nums, 0, middle));
+        int[] right = mergeSort(Arrays.copyOfRange(nums, middle, nums.length));
+
+        return merge(left, right);
+    }
+
+    private static int[] merge(int[] first, int[] second) {
+        int[] mix = new int[first.length + second.length];
+        int i = 0, j = 0, k = 0;
+
+        while (i < first.length && j < second.length) {
+            if (first[i] < second[j]) {
+                mix[k] = first[i];
+                i++;
+            } else {
+                mix[k] = second[j];
+                j++;
+            }
+            k++;
+        }
+
+        // At the end, it may be possible that one of the arrays it not complete
+        // copy the remaining elements. Please note that either of the loops will run
+        while (i < first.length) {
+            mix[k] = first[i];
+            i++;
+            k++;
+        }
+
+        while (j < second.length) {
+            mix[k] = second[j];
+            j++;
+            k++;
+        }
+        return mix;
+    }
+}

src/intermediate/Sorting.java

@@ -192,25 +192,25 @@ private static int getMaxIndex(int[] arr, int start, int lastIndex) {
     }
 
     public static void bubbleSort(int[] arr) {
-//        boolean isSwapped;
+        boolean isSwapped;
         // Get an outer for loop as a counter
         // Get an inner for loop for swapping elements of the array
         // if the current element is greater than the previous element, swap
         System.out.println(Arrays.toString(arr));
         for (int i = 0; i < arr.length; i++) {
-//            isSwapped = false;
+            isSwapped = false;
 
             for (int j = 1; j < arr.length - i; j++) {
                 if (arr[j] < arr[j - 1]) {
                     int temp = arr[j];
                     arr[j] = arr[j - 1];
                     arr[j - 1] = temp;
-//                    isSwapped = true;
+                    isSwapped = true;
                     System.out.println(Arrays.toString(arr));
                 }
             }
-//            if (!isSwapped) // if there was no swapping
-//                break;
+            if (!isSwapped) // if there was no swapping
+                break;
         }
     }