Today I have done leetcode's August LeetCoding Challenge with cpp.

August LeetCoding Challenge 10

Description

Convert Sorted Array to Binary Search Tree

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:

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:

Input: nums = [1,3]
Output: [3,1]
Explanation: [1,null,3] and [3,1] are both height-balanced BSTs.

Constraints:

• 1 <= nums.length <= 10^4
• -10^4 <= nums[i] <= 10^4
• nums is sorted in a strictly increasing order.

Solution

class Solution {
  TreeNode *construct(vector<int> &nums, int begin, int end) {
    if(begin > end) return nullptr;
    int mid = (begin + end) >> 1;
    TreeNode *root = new TreeNode(nums[mid]);
    root->left = construct(nums, begin, mid - 1);
    root->right = construct(nums, mid + 1, end);
    return root;
  }
public:
  TreeNode* sortedArrayToBST(vector<int>& nums) {
    int len = nums.size();
    return construct(nums, 0, len - 1);
  }
};

// Accepted
// 31/31 cases passed (8 ms)
// Your runtime beats 95.55 % of cpp submissions
// Your memory usage beats 75.67 % of cpp submissions (21.4 MB)