二叉搜索树的后序遍历判断

 1 public class Solution {
 2     public boolean VerifySquenceOfBST(int [] sequence) {
 3         if(sequence.length==0)
 4             return false;
 5           return helper(sequence,0,sequence.length-1);
 6     }
 7     public boolean helper(int[] arr, int l,int r)
 8     {
 9         if(l>=r)
10             return true;
11         for(int i=l;i<r;i++)
12         {
13             if(arr[i]>arr[r])
14             {
15                 for(int j=i;j<r;j++)
16                     if(arr[j]<arr[r])
17                         return false;
18                 return helper(arr,l,i-1)&&helper(arr,i,r-1);
19             }
20         }
21         return true;
22     }
23 }