分治法-递归
代码语言：javascript
复制/**
* Definition for a binary tree node.
* 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 {
public:
void recursive(vector<int>& nums, TreeNode* root, int left, int right) {
if (left > right) return;
int mid = (left right) / 2;
root->val = nums[mid];
if (left < mid)
root->left = new TreeNode(nums[(left mid) / 2]);
if (mid < right)
root->right = new TreeNode(nums[(mid right) / 2]);
recursive(nums, root->left, left, mid - 1);
recursive(nums, root->right, mid 1, right);
}
TreeNode* sortedArrayToBST(vector<int>& nums) {
if (nums.empty()) return nullptr;
TreeNode* root = new TreeNode(0);
recursive(nums, root, 0, nums.size() - 1);
return root;
}
};
