p108.cpp

#include <bits/stdc++.h>
using namespace std;

struct TreeNode
{
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode() : val(0), left(nullptr), right(nullptr) {}
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
    TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
};

class Solution
{
    TreeNode *solve(int start, int end, vector<int> &nums)
    {
        if (start > end)
        {
            return nullptr;
        }

        int mid = (start + end) / 2;
        TreeNode *root = new TreeNode(nums[mid]);
        root->left = solve(start, mid - 1, nums);
        root->right = solve(mid + 1, end, nums);
        return root;
    }

public:
    TreeNode *sortedArrayToBST(vector<int> &nums)
    {
        return solve(0, nums.size() - 1, nums);
    }
};
int main()
{
    vector<int> nums = {1, 2, 3, 4, 5, 6, 7};
    TreeNode *root = Solution().sortedArrayToBST(nums);
    return 0;
}