Convert Sorted List to Binary Search Tree

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Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.

解题思路:采用中序排列的方法递归地决定每个结点的数值；

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
//Definition for singly - linked list.
struct ListNode {
	int val;
	ListNode *next;
	ListNode(int x) : val(x), next(NULL) {}
	
};
//Definition for binary tree
struct TreeNode {
   int val;
   TreeNode *left;
   TreeNode *right;
   TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
void ListToBST(vector<ListNode*>::iterator Begin, vector<ListNode*>::iterator End, TreeNode*&root)
{
	if (Begin==End)
		return;
	auto len = distance(Begin,End);
	if ((int)len == 1){
		root = new TreeNode((*Begin)->val);
		return;
	}
	auto Iter_mid = Begin;
	advance(Iter_mid, len / 2);
	root = new TreeNode((*Iter_mid)->val);
	ListToBST(Begin, Iter_mid, root->left);
	ListToBST(Iter_mid + 1, End, root->right);
}
TreeNode *sortedListToBST(ListNode *head) {
	vector<ListNode*>NodeVector;
	for (; head != NULL; head = head->next)
		NodeVector.push_back(head);
	TreeNode* Root = NULL;
	ListToBST(NodeVector.begin(), NodeVector.end(), Root);
	return Root;
}

Convert Sorted List to Binary Search Tree

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原文地址：http://blog.csdn.net/li_chihang/article/details/43305803