Java Program to Perform Quick Sort on Large Number of Elements

This is a java program to sort the large number of elements using Quick Sort Technique. Quick sort uses a pivot element, where all the elements less that pivot are kept in one list and all the elements greater than pivot are kept in another list, and so on.

Here is the source code of the Java Program to Perform Quick Sort on Large Number of Elements. The Java program is successfully compiled and run on a Windows system. The program output is also shown below.

//This is a java program to sort large number of element using Quick Sort
import java.util.Random;
 
public class Quick_Sort 
{
    public static int N = 25;
    public static int[] sequence = new int[N];
 
    public static void QuickSort(int left, int right) 
    {
        if (right - left <= 0)
            return;
        else 
        {
            int pivot = sequence[right];
            int partition = partitionIt(left, right, pivot);
            QuickSort(left, partition - 1);
            QuickSort(partition + 1, right);
        }
    }
 
    public static int partitionIt(int left, int right, long pivot) 
    {
        int leftPtr = left - 1;
        int rightPtr = right;
        while (true) 
        {
            while (sequence[++leftPtr] < pivot)
                ;
            while (rightPtr > 0 && sequence[--rightPtr] > pivot)
                ;
 
            if (leftPtr >= rightPtr)
                break;
            else
                swap(leftPtr, rightPtr);
        }
        swap(leftPtr, right);
        return leftPtr;
    }
 
    public static void swap(int dex1, int dex2) 
    {
        int temp = sequence[dex1];
        sequence[dex1] = sequence[dex2];
        sequence[dex2] = temp;
    }
 
    static void printSequence(int[] sorted_sequence) 
    {
        for (int i = 0; i < sorted_sequence.length; i++)
            System.out.print(sorted_sequence[i] + " ");
    }
 
    public static void main(String args[]) 
    {
        System.out
                .println("Sorting of randomly generated numbers using QUICK SORT");
        Random random = new Random();
 
        for (int i = 0; i < N; i++)
            sequence[i] = Math.abs(random.nextInt(100));
 
        System.out.println("\nOriginal Sequence: ");
        printSequence(sequence);
        System.out.println("\nSorted Sequence: ");
        QuickSort(0, N - 1);
        printSequence(sequence);
 
    }
 
}

Output:

$ javac Quick_Sort.java
$ java Quick_Sort
 
Sorting of randomly generated numbers using QUICK SORT
 
Original Sequence: 
54 22 88 52 43 84 61 75 54 72 7 42 47 15 40 16 46 28 9 48 78 10 89 95 8 
Sorted Sequence: 
7 8 9 10 15 16 22 28 40 42 43 46 47 48 52 54 54 61 72 75 78 84 88 89 95