in place quicksort

quicksort.java

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

  public static void quickSort(int[] elements, int low, int high) {
    if(low >= high){
      return;
    }
    int pivot = partition(elements, low, high);
    quickSort(elements, low, pivot - 1);
    quickSort(elements, pivot + 1, high);
  }

  public static int partition(int[] elements, int low, int high) {
    int left = low;
    int right = high - 1;
    int pivot = elements[high];
    
    while(left <= right){
      while (left <= right && elements[left] < pivot){
        left++;
      }
      while (left <= right && elements[right] > pivot){
        right--;
      }
      if(left <= right){
        swap(elements, left, right);
        left++;
        right--;
      }
    }
          
    swap(elements, left, high);
    return left;
  }

  public static void swap(int[] elements, int a, int b) {
    int temp = elements[a];
      elements[a] = elements[b];
      elements[b] = temp;
  }

  public static void printArr(int[] arr){
    String str = "";
    for(int i : arr){
      str += i + ", ";
    }
    System.out.println(str);
  }