Sorting algorithm: Quicksort method

Quicksort.java

public class Quicksort {
	
	public void sort(int[] elements) {
		quickSort(elements, 0, elements.length-1);
	}

	/**
     	* Gets the position of the median of the three (left, right and 
     	* the element which position is in the center between them, and 
     	* moves the elements to order them
     	* @param elements Array with numbers to calculate the median of three
     	* @param left Position of the element on the left
     	* @param right Position of the element on the right
     	* @return Position of the median of three
     	*/
	private int median_of_three(int elements[], int left, int right){ 
		int center = (left + right) / 2;
		if (elements[left] > elements[center])
			Util.interchange(elements, left, center);
		if (elements[left] > elements[right])
			Util.interchange(elements, left, right);
		if (elements[center] > elements[right])
			Util.interchange(elements, center, right);
		return center;
	}
	
	/**
	* Interchanges element i and element j
	* @param elements Array with numbers
	* @param i Position of one element to be interchanged
	* @param j Position of the other element
	*/
	public void interchange(int[] elements, int i, int j) {
		int temp = elements[i];
		elements[i] = elements[j];
		elements[j] = temp;
	}
	
	private void quickSort(int elements[], int left, int right){
		int i = left;
		int j = right - 1;
		int pivot;
		
		if (left < right){ //if there is one element it is not necessary
			int center = median_of_three(elements, left, right);
			//if there are less than or equal to 3 elements, there are just ordered
			if ((right - left) >= 3){ 
				pivot = elements[center]; //choose the pivot
				interchange(elements, center, right); //hide the pivot

				do {         
			    		while (elements[i] <= pivot && i < right) i++; //first element > pivot
			    		while (elements[j] >= pivot && j > left) j--; //first element < pivot
			        	if (i < j) interchange(elements, i, j);
			   	} while (i < j);   //end while
				//we set the position of the pivot
				interchange(elements, i, right);
				quickSort(elements, left, i-1);
				quickSort(elements, i+1, right);		
			}
		} 
	}
  
}