Convert Sorted Array to Binary Search Tree Problem
Description
LeetCode Problem 108.
Given an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree.
A height-balanced binary tree is a binary tree in which the depth of the two subtrees of every node never differs by more than one.
Example 1:
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Input: nums = [-10,-3,0,5,9]
Output: [0,-3,9,-10,null,5]
Explanation: [0,-10,5,null,-3,null,9] is also accepted:
Example 2:
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Input: nums = [1,3]
Output: [3,1]
Explanation: [1,3] and [3,1] are both a height-balanced BSTs.
Constraints:
- 1 <= nums.length <= 10^4
- -10^4 <= nums[i] <= 10^4
- nums is sorted in a strictly increasing order.
Sample C++ Code
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class Solution {
public:
TreeNode *sortedArrayToBST(vector<int> &num) {
if(num.size() == 0) return NULL;
if(num.size() == 1) return new TreeNode(num[0]);
int middle = num.size()/2;
TreeNode* root = new TreeNode(num[middle]);
vector<int> leftInts(num.begin(), num.begin()+middle);
vector<int> rightInts(num.begin()+middle+1, num.end());
root->left = sortedArrayToBST(leftInts);
root->right = sortedArrayToBST(rightInts);
return root;
}
};