quicksort.java

import java.util.Scanner;

class quicksort {

    static void swap(int[] arr, int i, int j) {
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }

    static int partition(int[] arr, int low, int high) {

        int pivot = arr[high];

        int i = (low - 1);

        for (int j = low; j <= high - 1; j++) {

            if (arr[j] < pivot) {

                i++;
                swap(arr, i, j);
            }
        }
        swap(arr, i + 1, high);
        return (i + 1);
    }

    static void quickSort(int[] arr, int low, int high) {
        if (low < high) {

            int pi = partition(arr, low, high);

            quickSort(arr, low, pi - 1);
            quickSort(arr, pi + 1, high);
        }
    }

    // Function to print an array
    static void printArray(int[] arr, int size) {
        for (int i = 0; i < size; i++)
            System.out.print(arr[i] + " ");

        System.out.println();
    }

    public static void main(String[] args) {
        int n;
        Scanner sc = new Scanner(System.in);
        System.out.println("enter no of elements in an array :");
        n = sc.nextInt();
        int[] arr = new int[10];
        System.out.println("enter elements in an array:");
        for (int i = 0; i < n; i++) {
            arr[i] = sc.nextInt();
        }
        quickSort(arr, 0, n - 1);
        System.out.println("Sorted array: ");
        printArray(arr, n);
    }
}