判断整数序列是不是二元查找树的后续遍历

/*
* Copyright (c) 2011 alexingcool. All Rights Reserved.
*/
#include <iostream>

using namespace std;

int array[] = {5, 7, 6, 9, 11, 10, 8};
const int size = sizeof array / sizeof *array;

bool isPostOrder(int (&array)[size], int start, int end)
{
if(start >= end)
return true;

int pivot = array[end];
int i = start, j = end - 1;

while(i <= end - 1 && array[i] <= pivot)
i++;
while(j > 0 && array[j] >= pivot)
j--;

if(i != j + 1)
return false;
else
return isPostOrder(array, start, j) && isPostOrder(array, i, end - 1);
}

void main()
{
if(isPostOrder(array, 0 ,size - 1))
cout << "is post order" << endl;
else
cout << "not post order" << endl;
}