剑指offer二十：二叉搜索树的后序遍历序列

#include<iostream>
using namespace std;

typedef struct treenode
{
	int data;
	treenode* left;
	treenode* right;
}node,*pnode;


bool verfySquenceOfBST(int sequence[], int length)
{
	if (sequence == NULL || length <= 0)
		return false;
	int root = sequence[length - 1];
	int i = 0;
	for (i = 0; i < length - 1; i++)
	{
		if (sequence[i] > root)
			break;
	}
	for (int j = i; j < length - 1; j++)
	{
		if (sequence[j] < root)
			return false;
	}
	//判断左子树是不是二叉搜索树
	bool left = true;
	if (i > 0)
		left = verfySquenceOfBST(sequence, i);
	//判断右子树是不是二叉搜索树
	bool right = true;
	if (i < length - 1)
		right = verfySquenceOfBST(sequence + i, length - i - 1);
	
	return(left&&right);
}