Given an array where elements are sorted in ascending order, convert it to a height balanced BST.
Code:
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
|
/** * Definition for binary tree
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class
Solution {
public:
TreeNode *res;
TreeNode *BST(vector<int> &num, int
begin, int
end){
if(begin>end)
return
NULL;
int
mid=(begin+end)/2;
TreeNode *node = new
TreeNode(num[mid]);
node->left=BST(num,begin,mid-1);
node->right=BST(num,mid+1,end);
return
node;
}
TreeNode *sortedArrayToBST(vector<int> &num) {
return
BST(num,0,num.size()-1);
}
}; |