单指针快速排序

public class QuickSortTest {  public static void main(String[] args) {    int[] arr = {2,1,6,1,4};    quickSort(arr, 0, arr.length - 1);    print(arr);  }  private static void print(int[] arr) {    for (int i = 0; i < arr.length; i++) {      System.out.print(arr[i] + " ");    }  }  private static void quickSort(int[] arr, int p, int r) {    if (p < r) {      int q = partition(arr, p, r);      quickSort(arr, p, q - 1);      quickSort(arr, q + 1, r);    }  }  private static int partition(int[] arr, int pivot, int r) {    int p = pivot + 1;    int bigger = r;    while (p <= bigger) {      if (arr[p] <= arr[pivot]) {        p++;      } else {        swap(arr, p, bigger);        bigger--;      }    }    //最后还要一次交换    swap(arr, pivot, bigger);    return bigger;  }  private static void swap(int[] arr, int p, int bigger) {    //交换元素    int t = arr[p];    arr[p] = arr[bigger];    arr[bigger] = t;  }}