Bug fixes and improvements (#1572)

* Sync zh and zh-hant versions.

* Remove the polyfill.io link from mkdocs.yml

* Update contributors' info for code reviewers and en/zh-hant versions reviewers.

* Fix graph.md

* Update avatars for English version reviewers.

* Sync zh and zh-hant versions.

* Fix two_sum_brute_force.png

* Sync zh and zh-hant versions.
Optimize structrue of index.html.

* Format index.html

zh-hant/codes/rust/src/include/tree_node.rs

@@ -0,0 +1,92 @@
+/*
+ * File: tree_node.rs
+ * Created Time: 2023-02-27
+ * Author: xBLACKICEx (xBLACKICE@outlook.com), night-cruise (2586447362@qq.com)
+ */
+
+use std::cell::RefCell;
+use std::rc::Rc;
+
+/* 二元樹節點型別 */
+#[derive(Debug)]
+pub struct TreeNode {
+    pub val: i32,
+    pub height: i32,
+    pub parent: Option<Rc<RefCell<TreeNode>>>,
+    pub left: Option<Rc<RefCell<TreeNode>>>,
+    pub right: Option<Rc<RefCell<TreeNode>>>,
+}
+
+impl TreeNode {
+    /* 建構子 */
+    pub fn new(val: i32) -> Rc<RefCell<Self>> {
+        Rc::new(RefCell::new(Self {
+            val,
+            height: 0,
+            parent: None,
+            left: None,
+            right: None,
+        }))
+    }
+}
+
+#[macro_export]
+macro_rules! op_vec {
+    ( $( $x:expr ),* ) => {
+        vec![
+            $( Option::from($x).map(|x| x) ),*
+        ]
+    };
+}
+
+// 序列化編碼規則請參考：
+// https://www.hello-algo.com/chapter_tree/array_representation_of_tree/
+// 二元樹的陣列表示：
+// [1, 2, 3, 4, None, 6, 7, 8, 9, None, None, 12, None, None, 15]
+// 二元樹的鏈結串列表示：
+//             /——— 15
+//         /——— 7
+//     /——— 3
+//    |    \——— 6
+//    |        \——— 12
+// ——— 1
+//     \——— 2
+//        |    /——— 9
+//         \——— 4
+//             \——— 8
+
+/* 將串列反序列化為二元樹：遞迴 */
+fn vec_to_tree_dfs(arr: &[Option<i32>], i: usize) -> Option<Rc<RefCell<TreeNode>>> {
+    if i >= arr.len() || arr[i].is_none() {
+        return None;
+    }
+    let root = TreeNode::new(arr[i].unwrap());
+    root.borrow_mut().left = vec_to_tree_dfs(arr, 2 * i + 1);
+    root.borrow_mut().right = vec_to_tree_dfs(arr, 2 * i + 2);
+    Some(root)
+}
+
+/* 將串列反序列化為二元樹 */
+pub fn vec_to_tree(arr: Vec<Option<i32>>) -> Option<Rc<RefCell<TreeNode>>> {
+    vec_to_tree_dfs(&arr, 0)
+}
+
+/* 將二元樹序列化為串列：遞迴 */
+fn tree_to_vec_dfs(root: Option<&Rc<RefCell<TreeNode>>>, i: usize, res: &mut Vec<Option<i32>>) {
+    if let Some(root) = root {
+        // i + 1 is the minimum valid size to access index i
+        while res.len() < i + 1 {
+            res.push(None);
+        }
+        res[i] = Some(root.borrow().val);
+        tree_to_vec_dfs(root.borrow().left.as_ref(), 2 * i + 1, res);
+        tree_to_vec_dfs(root.borrow().right.as_ref(), 2 * i + 2, res);
+    }
+}
+
+/* 將二元樹序列化為串列 */
+pub fn tree_to_vec(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<Option<i32>> {
+    let mut res = vec![];
+    tree_to_vec_dfs(root.as_ref(), 0, &mut res);
+    res
+}