Discussion on: Merge Sort and Quick Sort!

import java.util.*;

public class QuickSort {

    public static void quickSort(int [] nums, int start, int end) {
        if (start <  end) {
            int partitionIndex = partition(nums, start, end);
            quickSort(nums, start, partitionIndex - 1);
            quickSort(nums, partitionIndex + 1, end);
        }
    }

    public static int partition(int [] nums, int start, int end) {
        int pivot = nums[end];
        int partitionIndex = start;
        for (int i=start; i<end; i++) {
            // lesser than pivot
            if (nums[i] <= pivot) {
                swap(nums, i, partitionIndex);
                partitionIndex += 1;
            }
        }
        swap(nums, end, partitionIndex);
        return partitionIndex;
    }

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

    public static void main(String [] args) {
        int [] nums = {5, 3, 2, 12, 100, 11, 1, 5, 6, 7,83, 4, 45, 56, 7, 4, 3,1};
        quickSort(nums, 0, nums.length - 1);
        for (int number : nums) {
            System.out.print(number + " ");
        }
    }
}