程序员面试100题之六，判断整数序列是不是二元查找树的后序遍历结果

// 100_6.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

bool verify(int * arr, int len)
{
	if(arr == NULL || len <=0)
		return false;

	int root = arr[len-1];

	int i=0;
	for(;i<len-1;i++)
	{
		if(arr[i]>root)
			break;
	}

	int j=i;
	for(;j<len-1;j++)
	{
		if(arr[j]<root)
			return false;
	}

	bool left = true;
	if(i>0)
		left = verify(arr,i);

	bool right = true;
	if(i<len-1)
		right = verify(arr+i,len-i-1);
	
	return left&&right;
}

int _tmain(int argc, _TCHAR* argv[])
{
	int arr1[] = {5,7,6,9,11,10,8};
	int arr2[] = {7,4,6,5};
	if(verify(arr1,7))
		printf("yes\n");
	else
		printf("no\n");
	if(verify(arr2,4))
		printf("yes\n");
	else
		printf("no\n");
	
	return 0;
}