Added Quick sort

java/Bubble_Sort.java

@@ -0,0 +1,13 @@
+public class BubbleSort {
+    public static void bubbleSort(int[] array){
+        for (int i = array.length-1; i >0; i--) {
+            for (int j = 0; j < i; j++) {
+                if (array[j]>array[j+1]){
+                    int temp = array[j];
+                    array[j]=array[j+1];
+                    array[j+1]=temp;
+                }
+            }
+        }
+    }
+}

java/Insertion_Sort.java

@@ -0,0 +1,13 @@
+public class InsertionSort {
+    public static void insertionSort(int[] array) {
+        for (int i = 1; i < array.length; i++) {
+            int temp = array[i];
+            int j =i-1;
+            while (j>-1 && temp<array[j]){
+                array[j+1]=array[j];
+                array[j]=temp;
+                j--;
+            }
+        }
+    }
+}

java/MergeSort.java

@@ -0,0 +1,48 @@
+
+import java.util.Arrays;
+
+public class MergeSort {
+
+    public static int[] merge(int[] array1, int[] array2){
+        int[] combined=new int[array1.length+ array2.length];
+        int index=0;
+        int i=0;
+        int j=0;
+
+        while (i< array1.length && j< array2.length){
+            if (array1[i]<array2[j]){
+                combined[index]=array1[i];
+                index++;
+                i++;
+            }else {
+                combined[index]=array2[j];
+                index++;
+                j++;
+            }
+        }
+        while (i< array1.length){
+            combined[index]=array1[i];
+            index++;
+            i++;
+        }
+        while (j< array2.length){
+            combined[index]=array2[j];
+            index++;
+            j++;
+        }
+        return combined;
+    }
+
+    public static int[] mergeSort(int[] array){
+        if (array.length==1)return array;
+        int mid = array.length/2;
+        int[] left = Arrays.copyOfRange(array,0,mid);
+        int[] right = Arrays.copyOfRange(array,mid,array.length);
+        return merge(mergeSort(left),mergeSort(right));
+    }
+
+    public static void main(String[] args) {
+        int[] array={45,67,23,89,32,55,23,66,34,2};
+        System.out.println(Arrays.toString(mergeSort(array)));
+    }
+}

java/QuickSort.java

@@ -0,0 +1,43 @@
+
+import java.util.Arrays;
+
+public class QuickSort {
+    private static void swap(int[] array, int firstIndex, int secondIndex){
+        int temp=array[firstIndex];
+        array[firstIndex]=array[secondIndex];
+        array[secondIndex]=temp;
+    }
+
+    private static int pivot(int[] array, int pivotIndex, int endIndex){
+        int swapIndex=pivotIndex;
+        for (int i = pivotIndex; i <=endIndex ; i++) {
+            if (array[i]<array[pivotIndex]){
+                swapIndex++;
+                swap(array,swapIndex,i);
+            }
+        }
+        swap(array,pivotIndex,swapIndex);
+        return swapIndex;
+    }
+
+    private static void quickSortHelper(int[] array, int left, int right) {
+        if (left<right){
+            int pivotIndex=pivot(array, left, right);
+            quickSortHelper(array, left, pivotIndex-1);
+            quickSortHelper(array, pivotIndex+1, right);
+        }
+    }
+
+    public static void quickSort(int[] array){
+        quickSortHelper(array,0, array.length-1);
+    }
+
+
+    public static void main(String[] args) {
+        int[] myArray={34,4,2,7,3,8,45,45,21,56,78,43,23};
+        quickSort(myArray);
+
+        System.out.println(Arrays.toString(myArray));
+    }
+
+}

java/SelectionSort.java

@@ -0,0 +1,18 @@
+
+public class SelectionSort {
+    public static void selectionSort(int[] array) {
+        for (int i = 0; i < array.length; i++) {
+            int minIndex=i;
+            for (int j = i+1; j < array.length; j++) {
+                if (array[j]<array[minIndex]){
+                    minIndex=j;
+                }
+            }
+            if (i!=minIndex){
+                int temp = array[i];
+                array[i]=array[minIndex];
+                array[minIndex]=temp;
+            }
+        }
+    }
+}