QuickSort.java

public class QuickSort {
    public static void quicksort(int arr[], int low, int high){

        if(low < high){
            int pivot = partition(arr,low,high);
            quicksort(arr, low, pivot-1);
            quicksort(arr, pivot+1, high);
        }
    }

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

        for(int j=low; j<high; j++)
        {
            if(arr[j] < pivot){
                i++;
                // Swap
                int temp = arr[i];
                arr[i] = arr[j];
                arr[j] = temp;
            }
        }
        i++;
        int temp = arr[i];
        arr[i] = pivot;
        arr[high] = temp;
        return i; //pivot index
    }

    public static void main(String[] args) {
        int arr[] = {6,3,9,5,2,8};
        int n = arr.length;
       quicksort(arr, 0, n-1);;
        for(int i=0; i<n; i++){
            System.out.print(arr[i]+" ");
        }
        System.out.println();
    }
}