translation: Add Python and Java code for EN version (#1345)

* Add the intial translation of code of all the languages

* test

* revert

* Remove

* Add Python and Java code for EN version

en/codes/java/utils/TreeNode.java

@@ -0,0 +1,73 @@
+/**
+ * File: TreeNode.java
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+package utils;
+
+import java.util.*;
+
+/* Binary tree node class */
+public class TreeNode {
+    public int val; // Node value
+    public int height; // Node height
+    public TreeNode left; // Reference to the left child node
+    public TreeNode right; // Reference to the right child node
+
+    /* Constructor */
+    public TreeNode(int x) {
+        val = x;
+    }
+
+    // For serialization encoding rules, refer to:
+    // https://www.hello-algo.com/chapter_tree/array_representation_of_tree/
+    // Array representation of the binary tree:
+    // [1, 2, 3, 4, None, 6, 7, 8, 9, None, None, 12, None, None, 15]
+    // Linked list representation of the binary tree:
+    //             /——— 15
+    //         /——— 7
+    //     /——— 3
+    //    |    \——— 6
+    //    |        \——— 12
+    // ——— 1
+    //     \——— 2
+    //        |    /——— 9
+    //         \——— 4
+    //             \——— 8
+
+    /* Deserialize a list into a binary tree: Recursively */
+    private static TreeNode listToTreeDFS(List<Integer> arr, int i) {
+        if (i < 0 || i >= arr.size() || arr.get(i) == null) {
+            return null;
+        }
+        TreeNode root = new TreeNode(arr.get(i));
+        root.left = listToTreeDFS(arr, 2 * i + 1);
+        root.right = listToTreeDFS(arr, 2 * i + 2);
+        return root;
+    }
+
+    /* Deserialize a list into a binary tree */
+    public static TreeNode listToTree(List<Integer> arr) {
+        return listToTreeDFS(arr, 0);
+    }
+
+    /* Serialize a binary tree into a list: Recursively */
+    private static void treeToListDFS(TreeNode root, int i, List<Integer> res) {
+        if (root == null)
+            return;
+        while (i >= res.size()) {
+            res.add(null);
+        }
+        res.set(i, root.val);
+        treeToListDFS(root.left, 2 * i + 1, res);
+        treeToListDFS(root.right, 2 * i + 2, res);
+    }
+
+    /* Serialize a binary tree into a list */
+    public static List<Integer> treeToList(TreeNode root) {
+        List<Integer> res = new ArrayList<>();
+        treeToListDFS(root, 0, res);
+        return res;
+    }
+}