New javascript solution to problem 230 and updated readme

README.md

@@ -348,7 +348,7 @@ LeetCode
 |233|[Number of Digit One](https://leetcode.com/problems/number-of-digit-one/)| [C++](./algorithms/cpp/numberOfDigitOne/NumberOfDigitOne.cpp)|Medium|
 |232|[Implement Queue using Stacks](https://leetcode.com/problems/implement-queue-using-stacks/)| [C++](./algorithms/cpp/implementQueueUsingStacks/ImplementQueueUsingStacks.cpp), [Java](./algorithms/java/src/myQueue/MyQueue.java)|Easy|
 |231|[Power of Two](https://leetcode.com/problems/power-of-two/)| [C++](./algorithms/cpp/powerOfTwo/PowerOfTwo.cpp)|Easy|
-|230|[Kth Smallest Element in a BST](https://leetcode.com/problems/kth-smallest-element-in-a-bst/)| [C++](./algorithms/cpp/kthSmallestElementInaBST/KthSmallestElementInABst.cpp), [Python](./algorithms/python/KthSmallestElementInABST/kthSmallest.py)|Medium|
+|230|[Kth Smallest Element in a BST](https://leetcode.com/problems/kth-smallest-element-in-a-bst/)| [C++](./algorithms/cpp/kthSmallestElementInaBST/KthSmallestElementInABst.cpp), [Python](./algorithms/python/KthSmallestElementInABST/kthSmallest.py), [Javascript](./algorithms/javascript/KthSmallestElementInABST/kthSmallest.js)|Medium|
 |229|[Majority Element II](https://leetcode.com/problems/majority-element-ii/) | [C++](./algorithms/cpp/majorityElement/majorityElement.II.cpp)|Medium|
 |228|[Summary Ranges](https://leetcode.com/problems/summary-ranges/)| [C++](./algorithms/cpp/summaryRanges/SummaryRanges.cpp)|Easy|
 |227|[Basic Calculator II](https://leetcode.com/problems/basic-calculator-ii/)| [C++](./algorithms/cpp/basicCalculator/BasicCalculator.II.cpp)|Medium|

algorithms/javascript/KthSmallestElementInABST/kthSmallest.js

@@ -0,0 +1,16 @@
+/**
+ * @param {TreeNode} root
+ * @param {number} k
+ * @return {number}
+ */
+var kthSmallest = function(root, k) {
+    let vals = [];
+    (function dfs(node) {
+      if (vals.length != k) { //no need to keep going after reach k-th number
+        if (node.left) dfs(node.left); //go left first
+        vals.push(node.val); //finished going left, now start adding values
+        if (node.right) dfs(node.right); //if have right, go there and repeat process
+      }  
+    })(root) // IFFE Immediately Invoking Function Expression, starting from root.
+    return vals[k-1]; //return element, but as i mentioned in the descript, don't need this full array, just the k-th elm
+  };