数组分区—荷兰国旗问题？

package com.harrison.class03;
public class Code04_Netherlands {
  public static int[] netherlands(int[] arr, int L, int R) {
    if (L > R) {
      return new int[] { -1, -1 };
    }
    if (L == R) {
      return new int[] { L, R };
    }
    int less = L - 1;
    int more = R;
    int i = L;
    while (i < more) {
      if (arr[i] == arr[R]) {
        i++;
      } else if (arr[i] < arr[R]) {
        swap(arr, i++, ++less);
      } else {
        swap(arr, i, --more);
      }
      // L...less less+1...more-1 more...R-1 R
      // L...less less+1..........more more+1...R
      swap(arr, more, R);
    }
    return new int[] { less + 1, more };
  }
  public static void swap(int[] arr, int i, int j) {
    int t = arr[i];
    arr[i] = arr[j];
    arr[j] = t;
  }
  public static void main(String[] args) {
    int[] arr= {9,32,3,4,-3,4,3,90,-3,9};
    int[] ans=netherlands(arr, 0, arr.length-1);
    for(int i=0; i<ans.length; i++) {
      System.out.print(ans[i]+" ");
    }
    // -3 -3 3 3 4 4 | 9 9 | 32 90
    // 6,7
  }
}