Thuật toán quicksort trong java

public class QuickSort {
   public static void main(String[] args) {
      int[] arr = {10, 7, 8, 9, 1, 5};
      int n = arr.length;
      
      quickSort(arr, 0, n-1);
      
      System.out.println("Mảng đã được sắp xếp:");
      for(int i = 0; i < n; i++) {
         System.out.print(arr[i] + " ");
      }
   }
   
   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++;
            
            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;
   }
}