LeetCode题解之 Convert Sorted Array to Binary Search Tree

1、题目描述

2、问题分析

使用二分法即可。

3、代码

 TreeNode* sortedArrayToBST(vector<int>& nums) {
         if (nums.size() == )
             return NULL;

         int left = ;
         int right = nums.size() - ;

         TreeNode *node = new TreeNode();
         BST(node->left,nums, left, right);
         return node->left;

     }

     void BST(TreeNode   * &parent, vector<int> &nums,int left, int right)
     {

         if (left <= right) {
             int mid = (left + right)/;
             TreeNode *node = new TreeNode(nums[mid]);
             parent = node;
             BST(node->left, nums, left, mid - );
             BST(node->right, nums, mid + , right);
         } else {
             return ;
         }
     }