QuickSort.java

public class QuickSort {

    public static void main(String[] args) {
        int[] array = {9, 7, 5, 11, 12, 2, 14, 3, 10, 6};
        int n = array.length;

        System.out.println("Original array:");
        printArray(array);

        quickSort(array, 0, n - 1);

        System.out.println("Sorted array:");
        printArray(array);
    }

    public static void quickSort(int[] array, int low, int high) {
        if (low < high) {
            int pivotIndex = partition(array, low, high);

            quickSort(array, low, pivotIndex - 1);
            quickSort(array, pivotIndex + 1, high);
        }
    }

    public static int partition(int[] array, int low, int high) {
        int pivot = array[high];
        int i = (low - 1);

        for (int j = low; j <= high - 1; j++) {
            if (array[j] < pivot) {
                i++;
                swap(array, i, j);
            }
        }

        swap(array, i + 1, high);
        return i + 1;
    }

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

    public static void printArray(int[] array) {
        for (int num : array) {
            System.out.print(num + " ");
        }
        System.out.println();
    }
}