QuickSort.java

class QuickSort {

  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++;
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
      }
    }
    int temp = arr[i + 1];
    arr[i + 1] = arr[high];
    arr[high] = temp;

    return i + 1;
  }

  void sort(int arr[], int low, int high) {
    if (low < high) {
      int pi = partition(arr, low, high);
      sort(arr, low, pi - 1);
      sort(arr, pi + 1, high);
    }
  }
}