[LeetCode] Convert Sorted Array to Binary Search Tree, Solution

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

» Solve this problem

[Thoughts]

[Code]

1:       TreeNode *sortedArrayToBST(vector<int> &num) {  
2:            return BuildTree(num, 0, num.size()-1);  
3:       }  
4:       TreeNode *BuildTree(vector<int> &num, int start, int end)  
5:       {  
6:            if(start>end) return NULL;  
7:            if(start == end) return new TreeNode(num[start]);  
8:            int mid = (start+end)/2;  
9:            TreeNode *node = new TreeNode(num[mid]);  
10:           node->left = BuildTree(num, start, mid-1);  
11:           node->right = BuildTree(num, mid+1, end);  
12:           return node;  
13:       }