class Solution { public: void rec(TreeNode* pRoot, vector<TreeNode*> &ret){ if(pRoot!=NULL){ rec(pRoot->left, ret); ret.push_back(pRoot); rec(pRoot->right, ret); } } TreeNode* KthNode(TreeNode* pRoot, int k) { if(k<1||pRoot==NULL) return NULL; //将二叉搜索树按照中序遍历(有序序列)存储在vector中 vector...