[ PS ] : Kth Smallest Element in a BST

Author: uraflower

kth-smallest-element-in-a-bst/uraflower.js

@@ -0,0 +1,29 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @param {number} k
+ * @return {number}
+ */
+const kthSmallest = function (root, k) {
+    const sorted = [];
+
+    const traverse = function (root) {
+        if (!root) return;
+        traverse(root.left);
+        sorted.push(root.val);
+        traverse(root.right);
+    }
+
+    traverse(root);
+    return sorted[k - 1];
+};
+
+// 시간복잡도: O(n)
+// 공간복잡도: O(n) (배열)