Updated markdown files

Author: Zanger67/leetcode

markdowns/Questions_By_Code_Length.md

@@ -59,6 +59,7 @@ Calculations are based on the code files's byte sizes.
 | 2206 | [Divide Array Into Equal Pairs](<https://leetcode.com/problems/divide-array-into-equal-pairs>)                                                                                             | Easy    |                | [solution](<_2206. Divide Array Into Equal Pairs.md>)                                               | c, py                                       | Jun 08, 2024    |
 | 3233 | Weekly Contest 408 - q2 - [Find the Count of Numbers Which Are Not Special](<https://leetcode.com/problems/find-the-count-of-numbers-which-are-not-special>)                               | Medium  | Contest        | [solution](<_3233. Find the Count of Numbers Which Are Not Special.md>)                             | java, py                                    | Jul 28, 2024    |
 | 1087 | [Brace Expansion](<https://leetcode.com/problems/brace-expansion>)                                                                                                                         | Medium  |                | [solution](<_1087. Brace Expansion.md>)                                                             | py                                          | Jun 15, 2024    |
+|  606 | [Construct String from Binary Tree](<https://leetcode.com/problems/construct-string-from-binary-tree>)                                                                                     | Medium  |                | [solution](<_606. Construct String from Binary Tree.md>)                                            | java, py                                    | Aug 04, 2024    |
 | 2390 | [Removing Stars From a String](<https://leetcode.com/problems/removing-stars-from-a-string>)                                                                                               | Medium  |                | [solution](<_2390. Removing Stars From a String.md>)                                                | java, py                                    | Jun 02, 2024    |
 | 1230 | [Toss Strange Coins](<https://leetcode.com/problems/toss-strange-coins>)                                                                                                                   | Medium  | Weekly Premium | [solution](<_1230. Toss Strange Coins.md>)                                                          | c, java, py                                 | Jul 29, 2024    |
 | 1992 | [Find All Groups of Farmland](<https://leetcode.com/problems/find-all-groups-of-farmland>)                                                                                                 | Medium  |                | [solution](<_1992. Find All Groups of Farmland.md>)                                                 | java, py                                    | Jun 24, 2024    |
@@ -136,7 +137,6 @@ Calculations are based on the code files's byte sizes.
 | 1122 | [Relative Sort Array](<https://leetcode.com/problems/relative-sort-array>)                                                                                                                 | Easy    | Daily          | [solution](<_1122. Relative Sort Array.md>)                                                         | java, py                                    | Jun 11, 2024    |
 | 1209 | [Remove All Adjacent Duplicates in String II](<https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string-ii>)                                                                 | Medium  |                | [solution](<_1209. Remove All Adjacent Duplicates in String II.md>)                                 | py                                          | Jun 19, 2024    |
 | 1171 | [Remove Zero Sum Consecutive Nodes from Linked List](<https://leetcode.com/problems/remove-zero-sum-consecutive-nodes-from-linked-list>)                                                   | Medium  |                | [solution](<_1171. Remove Zero Sum Consecutive Nodes from Linked List.md>)                          | py                                          | Jun 15, 2024    |
-|  606 | [Construct String from Binary Tree](<https://leetcode.com/problems/construct-string-from-binary-tree>)                                                                                     | Medium  |                | [solution](<_606. Construct String from Binary Tree.md>)                                            | java, py                                    | Aug 04, 2024    |
 | 2665 | [Counter II](<https://leetcode.com/problems/counter-ii>)                                                                                                                                   | Easy    |                | [solution](<_2665. Counter II.md>)                                                                  | js                                          | Jul 09, 2024    |
 |   78 | [Subsets](<https://leetcode.com/problems/subsets>)                                                                                                                                         | Medium  | N150           | [solution](<_78. Subsets.md>)                                                                       | py                                          | Jun 02, 2024    |
 |  791 | [Custom Sort String](<https://leetcode.com/problems/custom-sort-string>)                                                                                                                   | Medium  |                | [solution](<_791. Custom Sort String.md>)                                                           | java                                        | Jun 24, 2024    |

markdowns/_606. Construct String from Binary Tree.md

@@ -20,9 +20,52 @@
 
 ## Solutions
 
+- [m606 v2 String Builder.java](<../my-submissions/m606 v2 String Builder.java>)
 - [m606.java](<../my-submissions/m606.java>)
 - [m606.py](<../my-submissions/m606.py>)
 ### Java
+#### [m606 v2 String Builder.java](<../my-submissions/m606 v2 String Builder.java>)
+```Java
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode() {}
+ *     TreeNode(int val) { this.val = val; }
+ *     TreeNode(int val, TreeNode left, TreeNode right) {
+ *         this.val = val;
+ *         this.left = left;
+ *         this.right = right;
+ *     }
+ * }
+ */
+class Solution {
+    public String tree2str(TreeNode root) {
+        return helper(root, new StringBuilder()).toString();
+    }
+
+    public StringBuilder helper(TreeNode curr, StringBuilder sb) {
+        sb.append(curr.val);
+
+        if (curr.left != null) {
+            sb.append("(");
+            helper(curr.left, sb);
+            sb.append(")");
+        } else if (curr.right != null) {
+            sb.append("()");
+        }
+        if (curr.right != null) {
+            sb.append("(");
+            helper(curr.right, sb);
+            sb.append(")");
+        }
+        return sb;
+    }
+}
+```
+
 #### [m606.java](<../my-submissions/m606.java>)
 ```Java
 /**