Quick sort Topic 14

package com.array;
import java.util.Arrays;
import java.util.Scanner;
import static com.array.quicksortmethods.quickSort;
public class quicksortmain {
    public static void main(String[] args) {
Scanner input = new Scanner(System.in);
        System.out.println("Input the number of elements /N/ :");
        int N = input.nextInt();

        int[] arr = new int[N];

        for (int i = 0; i < N; i++) {
            System.out.printf("Input element [%d] : ", i);
            arr[i] = input.nextInt();
        }

        System.out.println("Before sorting : " + Arrays.toString(arr));

        quickSort(arr,0,N - 1);

        System.out.println("After sorting : " + Arrays.toString(arr));
    }
}





package com.array;
public class quicksortmethods {

    public 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);

        }
    }

    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[j];
                arr[j] = arr[i];
                arr[i] = temp;

            }
        }
        //put the pivot element at the right position
       int temp = arr[high];
        arr[high] = arr[i + 1];
        arr[i + 1] = temp;
        return i + 1;
    }

}