题解 | #二叉搜索树的第k个节点#
二叉搜索树的第k个节点
https://www.nowcoder.com/practice/57aa0bab91884a10b5136ca2c087f8ff
// 中序遍历 class Solution { public: public: int KthNode(TreeNode* proot, int k) { if (proot == nullptr) return -1; if (k == 0) return -1; std::vector<int> vec; Inorder(proot, vec); if (vec.size() >= k) { return vec[k - 1]; } else return -1; } private: void Inorder(TreeNode* root, std::vector<int>& inputVec) { // 中序遍历 if (root->left != nullptr) { Inorder(root->left, inputVec); } inputVec.push_back(root->val); if (root->right != nullptr) { Inorder(root->right, inputVec); } } };