题目：

Given an array where elements are sorted in ascending order, convert it to a height balanced BST.

思路：从一个数组中找到中间的元素作为BST的根，然后坐边的作为左子树，右边的作为右子树，递归调用

#include <iostream>
#include <stack>
#include <vector>
#include <deque>
#include <stdlib.h>
using namespace std;

typedef struct Bin_tree BinTree;
struct Bin_tree
{
       int value;
       BinTree* right;
       BinTree* left;
};
BinTree* helper(vector<int>& vec,int low,int high)
{
	BinTree* node=NULL;
	if(low > high)
		return NULL;
	int mid = low+(high-low)/2;
	node = new BinTree;
	node->value = vec[mid];
	node->left = NULL;
	node->right = NULL;
	node->left = helper(vec,low,mid-1);
	node->right = helper(vec,mid+1,high);
	return node;
}

BinTree* ConvertBST(vector<int>& vec)
{
	BinTree* root=NULL;
	if(vec.size() <=0)
		return root;
	root = helper(vec,0,vec.size()-1);
}
void Inorder(BinTree* root)
{
     if(root == NULL)
       return ;
     Inorder(root->left);
     cout<<root->value<<endl;
     Inorder(root->right);
     }

int main()
<span style="font-family:'Helvetica Neue',arial,sans-serif;">{</span>	<span style="font-family:'Helvetica Neue',arial,sans-serif;"> </span>
    BinTree* second=NULL;
  <span style="font-family:'Helvetica Neue',arial,sans-serif;"> </span>
    int sec[]={4,5,6,10,14,16};
    vector<int> vec(sec,sec+sizeof(sec)/sizeof(int));
    second = ConvertBST(vec);
	Inorder(second);
	return 0;
}