Program to perform Selection Sort.

Code:

public class MySelectionSort
{
    public static int[] doSelectionSort(int[] arr)
    {    
        for (int i = 0; i < arr.length - 1; i++)
        {
            int index = i;
            for (int j = i + 1; j < arr.length; j++)
                if (arr[j] < arr[index])
                    index = j;
     
            int smallerNumber = arr[index]; 
            arr[index] = arr[i];
            arr[i] = smallerNumber;
        }
        return arr;
    }
    
    public static void main(String a[])
    {        
        int[] arr1 = {10,34,2,56,7,67,88,42};
        int[] arr2 = doSelectionSort(arr1);
        for(int i:arr2)
        {
            System.out.println(i);
           
        }
    }
}

Program to perform Insertion Sort.

Code:

public class MyInsertionSort
{
    public static void main(String a[])
    {
        int[] arr1 = {10,34,2,56,7,67,88,42};
        int[] arr2 = doInsertionSort(arr1);
        for(int i:arr2)
        {
            System.out.print(i);
            System.out.print(", ");
        }
    }
    
    public static int[] doInsertionSort(int[] input)
    {    
        int temp;
        for (int i = 1; i < input.length; i++)
        {
            for(int j = i ; j > 0 ; j--)
            {
                if(input[j] < input[j-1])
                {
                    temp = input[j];
                    input[j] = input[j-1];
                    input[j-1] = temp;
                }
            }
        }
        return input;
    }
}

Program to perform Quick Sort.

Code:

public class QuickSort
{    
    private int array[];
    private int length;
    public void sort(int[] inputArr)
    {        
        if (inputArr == null || inputArr.length == 0)
        {
            return;
        }
        this.array = inputArr;
        length = inputArr.length;
        quickSort(0, length - 1);
    }

    private void quickSort(int lowerIndex, int higherIndex)
    {    
        int i = lowerIndex;
        int j = higherIndex;
        // calculate pivot number, I am taking pivot as middle index number
        int pivot = array[lowerIndex+(higherIndex-lowerIndex)/2];
        // Divide into two arrays
        while (i <= j)
        {        
            while (array[i] < pivot)
            {
                i++;
            }
            while (array[j] > pivot)
            {
                j--;
            }
            if (i <= j)
            {
                exchangeNumbers(i, j);
                //move index to next position on both sides
                i++;
                j--;
            }
        }
        // call quickSort() method recursively
        if (lowerIndex < j)
            quickSort(lowerIndex, j);
        if (i < higherIndex)
            quickSort(i, higherIndex);
    }

    private void exchangeNumbers(int i, int j)
    {
        int temp = array[i];
        array[i] = array[j];
        array[j] = temp;
    }
    
    public static void main(String a[])
    {        
        QuickSort sorter = new QuickSort();
        int[] input = {24,2,45,20,56,75,2,56,99,53,12};
        sorter.sort(input);
        for(int i:input)
        {
            System.out.print(i);
            System.out.print(" ");
        }
    }
}

Program to perform Merge Sort.

Code:

public class MergeSort
{    
    private int[] array;
    private int[] tempMergArr;
    private int length;
    public static void main(String args[])
    {        
        int[] inputArr = {45,23,11,89,77,98,4,28,65,43};
        MergeSort mms = new MergeSort();
        mms.sort(inputArr);
        for(int i:inputArr)
        {
            System.out.print(i);
            System.out.print(" ");
        }
    }
    
    public void sort(int inputArr[])
    {
        this.array = inputArr;
        this.length = inputArr.length;
        this.tempMergArr = new int[length];
        doMergeSort(0, length - 1);
    }

    private void doMergeSort(int lowerIndex, int higherIndex)
    {        
        if (lowerIndex < higherIndex)
        {
            int middle = lowerIndex + (higherIndex - lowerIndex) / 2;
            // Below step sorts the left side of the array
            doMergeSort(lowerIndex, middle);
            // Below step sorts the right side of the array
            doMergeSort(middle + 1, higherIndex);
            // Now merge both sides
            mergeParts(lowerIndex, middle, higherIndex);
        }
    }

    private void mergeParts(int lowerIndex, int middle, int higherIndex)
    {
        for (int i = lowerIndex; i <= higherIndex; i++)
        {
            tempMergArr[i] = array[i];
        }
        int i = lowerIndex;
        int j = middle + 1;
        int k = lowerIndex;
        while (i <= middle && j <= higherIndex)
        {
            if (tempMergArr[i] <= tempMergArr[j])
            {
                array[k] = tempMergArr[i];
                i++;
            }
            else
            {
                array[k] = tempMergArr[j];
                j++;
            }
            k++;
        }
        while (i <= middle)
        {
            array[k] = tempMergArr[i];
            k++;
            i++;
        }
     }
}

Program to perform Bubble Sort.

Code:

public class Bubble
{
   public static void main(String args[])
   {         
            int[] a = {4, 85, 7, 1, 0, 36, -5, 48};
           for (int i = 0; i < a.length - 1; i++)
           {
                   for (int j = 0; j < a.length - 1 - i; j++)
                  {
                        if (a[j + 1] < a[j])
                       {
                             int temp = a[j];
                             a[j] = a[j + 1];
                             a[j + 1] = temp;
                       }
                  }
             }
            for (int i = 0; i < a.length - 1; i++)
           {
               System.out.println(a[i]);
           }
     }
}