【剑指offer】十六，二叉搜索树的后序遍历序列

 1 public class Solution {
 2    public boolean VerifySquenceOfBST(int [] sequence) {
 3         boolean res  = false ;
 4         if(sequence.length==0||sequence==null){
 5             return res ;
 6         }
 7         else if(sequence.length==1){
 8             res = true ;
 9             return res ;
10         }
11         else res = verifyQquenceOfBST(sequence ,0,sequence.length-1) ;
12         return res ;
13     }
14     public boolean verifyQquenceOfBST (int[] array ,int begin,int end ){
15         boolean res  = false ;
16         if(begin==end){
17             return  true ;
18         }
19         int mid = begin ;
20         while(array[mid]<array[end]&&mid<end){
21             mid++ ;
22         }
23         if(mid==end){
24             res = verifyQquenceOfBST ( array ,begin,end-1 ) ;
25         }
26         else if(mid==begin){
27             for(int i = begin ; i<end ;i++){
28                 if(array[i]<array[end]){
29                     return false ;
30                 }
31                  
32             }
33             res = verifyQquenceOfBST ( array ,begin,end-1 ) ;
34         }
35         else{
36                 for(int i = mid ; i<end ;i++){
37                 if(array[i]<array[end]){
38                     return false ;
39                 }
40             }
41             res = verifyQquenceOfBST ( array ,begin,mid-1 ) &&verifyQquenceOfBST ( array ,mid,end-1 ) ;
42         }
43         return res ;
44     }
45 }