二叉搜索树的后序遍历序列

题目描述

class Solution {
public:
bool isBST(vector<int> &s,int a,int b)
{
if(b<a)
return false;
if(b==a)
return true;
int root=s[b];
int i,j;
for(i=a;i<=b-1;i++)
if(s[i]>root)break;
bool  left=true;
if(i>a)
left=isBST(s,a,i-1);
for(j=i;j<=b-1;j++)
if(s[j]<root)return false;
bool right=true;
if(i<b-1) return isBST(s,i,b-1);
return left&&right;

}
bool VerifySquenceOfBST(vector<int> sequence) {
if(sequence.size()<0||sequence.size()==0)
return false;
if(sequence.size()==1)
return true;
int len=sequence.size();
return isBST(sequence,0,len-1);

}
};