C
1struct TreeNode{
2 int val;
3 TreeNode* left;
4 TreeNode* right;
5 TreeNode(int x): val(x), left(nullptr), right(nullptr){}
6};
C
1TreeNode* insertNode(TreeNode* root, int x){,[object Object],
2if(root== nullptr){,[object Object],
3return new TreeNode(x);,[object Object],
4},[object Object],
5if(x< root->val){,[object Object],
6root->right= insertNode(root->right, x);,[object Object],
7} else{,[object Object],
8root->left= insertNode(root->left, x);,[object Object],
9},[object Object],
10return root;,[object Object],
11},[object Object],