Add Leetcode TOP

Author: kothariji

Leetcode - Top Interview Questions/230. Kth Smallest Element in a BST.cpp

@@ -0,0 +1,31 @@
+/**
+ * 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 inorder(TreeNode *root, vector<int> &v1, int k)
+    {
+        if (v1.size() >= k)
+            return;
+        if (root == NULL)
+            return;
+        inorder(root->left, v1, k);
+        v1.push_back(root->val);
+        inorder(root->right, v1, k);
+    }
+    int kthSmallest(TreeNode *root, int k)
+    {
+        vector<int> v1;
+        inorder(root, v1, k);
+        return v1[k - 1];
+    }
+};