Translate all code to English (#1836)

* Review the EN heading format.

* Fix pythontutor headings.

* Fix pythontutor headings.

* bug fixes

* Fix headings in **/summary.md

* Revisit the CN-to-EN translation for Python code using Claude-4.5

* Revisit the CN-to-EN translation for Java code using Claude-4.5

* Revisit the CN-to-EN translation for Cpp code using Claude-4.5.

* Fix the dictionary.

* Fix cpp code translation for the multipart strings.

* Translate Go code to English.

* Update workflows to test EN code.

* Add EN translation for C.

* Add EN translation for CSharp.

* Add EN translation for Swift.

* Trigger the CI check.

* Revert.

* Update en/hash_map.md

* Add the EN version of Dart code.

* Add the EN version of Kotlin code.

* Add missing code files.

* Add the EN version of JavaScript code.

* Add the EN version of TypeScript code.

* Fix the workflows.

* Add the EN version of Ruby code.

* Add the EN version of Rust code.

* Update the CI check for the English version  code.

* Update Python CI check.

* Fix cmakelists for en/C code.

* Fix Ruby comments

en/codes/javascript/chapter_tree/array_binary_tree.js

@@ -0,0 +1,147 @@
+/**
+ * File: array_binary_tree.js
+ * Created Time: 2023-08-06
+ * Author: yuan0221 (yl1452491917@gmail.com)
+ */
+
+const { arrToTree } = require('../modules/TreeNode');
+const { printTree } = require('../modules/PrintUtil');
+
+/* Binary tree class represented by array */
+class ArrayBinaryTree {
+    #tree;
+
+    /* Constructor */
+    constructor(arr) {
+        this.#tree = arr;
+    }
+
+    /* List capacity */
+    size() {
+        return this.#tree.length;
+    }
+
+    /* Get value of node at index i */
+    val(i) {
+        // If index out of bounds, return null to represent empty position
+        if (i < 0 || i >= this.size()) return null;
+        return this.#tree[i];
+    }
+
+    /* Get index of left child node of node at index i */
+    left(i) {
+        return 2 * i + 1;
+    }
+
+    /* Get index of right child node of node at index i */
+    right(i) {
+        return 2 * i + 2;
+    }
+
+    /* Get index of parent node of node at index i */
+    parent(i) {
+        return Math.floor((i - 1) / 2); // Floor division
+    }
+
+    /* Level-order traversal */
+    levelOrder() {
+        let res = [];
+        // Traverse array directly
+        for (let i = 0; i < this.size(); i++) {
+            if (this.val(i) !== null) res.push(this.val(i));
+        }
+        return res;
+    }
+
+    /* Depth-first traversal */
+    #dfs(i, order, res) {
+        // If empty position, return
+        if (this.val(i) === null) return;
+        // Preorder traversal
+        if (order === 'pre') res.push(this.val(i));
+        this.#dfs(this.left(i), order, res);
+        // Inorder traversal
+        if (order === 'in') res.push(this.val(i));
+        this.#dfs(this.right(i), order, res);
+        // Postorder traversal
+        if (order === 'post') res.push(this.val(i));
+    }
+
+    /* Preorder traversal */
+    preOrder() {
+        const res = [];
+        this.#dfs(0, 'pre', res);
+        return res;
+    }
+
+    /* Inorder traversal */
+    inOrder() {
+        const res = [];
+        this.#dfs(0, 'in', res);
+        return res;
+    }
+
+    /* Postorder traversal */
+    postOrder() {
+        const res = [];
+        this.#dfs(0, 'post', res);
+        return res;
+    }
+}
+
+/* Driver Code */
+// Initialize binary tree
+// Here we use a function to generate a binary tree directly from an array
+const arr = Array.of(
+    1,
+    2,
+    3,
+    4,
+    null,
+    6,
+    7,
+    8,
+    9,
+    null,
+    null,
+    12,
+    null,
+    null,
+    15
+);
+
+const root = arrToTree(arr);
+console.log('\nInitialize binary tree\n');
+console.log('Array representation of binary tree:');
+console.log(arr);
+console.log('Linked list representation of binary tree:');
+printTree(root);
+
+// Binary tree class represented by array
+const abt = new ArrayBinaryTree(arr);
+
+// Access node
+const i = 1;
+const l = abt.left(i);
+const r = abt.right(i);
+const p = abt.parent(i);
+console.log('\nCurrent node index is ' + i + ', value is ' + abt.val(i));
+console.log(
+    'Its left child node index is ' + l + ', value is ' + (l === null ? 'null' : abt.val(l))
+);
+console.log(
+    'Its right child node index is ' + r + ', value is ' + (r === null ? 'null' : abt.val(r))
+);
+console.log(
+    'Its parent node index is ' + p + ', value is ' + (p === null ? 'null' : abt.val(p))
+);
+
+// Traverse tree
+let res = abt.levelOrder();
+console.log('\nLevel-order traversal is:' + res);
+res = abt.preOrder();
+console.log('Preorder traversal is:' + res);
+res = abt.inOrder();
+console.log('Inorder traversal is:' + res);
+res = abt.postOrder();
+console.log('Postorder traversal is:' + res);

en/codes/javascript/chapter_tree/avl_tree.js

@@ -0,0 +1,208 @@
+/**
+ * File: avl_tree.js
+ * Created Time: 2023-02-05
+ * Author: what-is-me (whatisme@outlook.jp)
+ */
+
+const { TreeNode } = require('../modules/TreeNode');
+const { printTree } = require('../modules/PrintUtil');
+
+/* AVL tree */
+class AVLTree {
+    /* Constructor */
+    constructor() {
+        this.root = null; // Root node
+    }
+
+    /* Get node height */
+    height(node) {
+        // Empty node height is -1, leaf node height is 0
+        return node === null ? -1 : node.height;
+    }
+
+    /* Update node height */
+    #updateHeight(node) {
+        // Node height equals the height of the tallest subtree + 1
+        node.height =
+            Math.max(this.height(node.left), this.height(node.right)) + 1;
+    }
+
+    /* Get balance factor */
+    balanceFactor(node) {
+        // Empty node balance factor is 0
+        if (node === null) return 0;
+        // Node balance factor = left subtree height - right subtree height
+        return this.height(node.left) - this.height(node.right);
+    }
+
+    /* Right rotation operation */
+    #rightRotate(node) {
+        const child = node.left;
+        const grandChild = child.right;
+        // Using child as pivot, rotate node to the right
+        child.right = node;
+        node.left = grandChild;
+        // Update node height
+        this.#updateHeight(node);
+        this.#updateHeight(child);
+        // Return root node of subtree after rotation
+        return child;
+    }
+
+    /* Left rotation operation */
+    #leftRotate(node) {
+        const child = node.right;
+        const grandChild = child.left;
+        // Using child as pivot, rotate node to the left
+        child.left = node;
+        node.right = grandChild;
+        // Update node height
+        this.#updateHeight(node);
+        this.#updateHeight(child);
+        // Return root node of subtree after rotation
+        return child;
+    }
+
+    /* Perform rotation operation to restore balance to this subtree */
+    #rotate(node) {
+        // Get balance factor of node
+        const balanceFactor = this.balanceFactor(node);
+        // Left-leaning tree
+        if (balanceFactor > 1) {
+            if (this.balanceFactor(node.left) >= 0) {
+                // Right rotation
+                return this.#rightRotate(node);
+            } else {
+                // First left rotation then right rotation
+                node.left = this.#leftRotate(node.left);
+                return this.#rightRotate(node);
+            }
+        }
+        // Right-leaning tree
+        if (balanceFactor < -1) {
+            if (this.balanceFactor(node.right) <= 0) {
+                // Left rotation
+                return this.#leftRotate(node);
+            } else {
+                // First right rotation then left rotation
+                node.right = this.#rightRotate(node.right);
+                return this.#leftRotate(node);
+            }
+        }
+        // Balanced tree, no rotation needed, return directly
+        return node;
+    }
+
+    /* Insert node */
+    insert(val) {
+        this.root = this.#insertHelper(this.root, val);
+    }
+
+    /* Recursively insert node (helper method) */
+    #insertHelper(node, val) {
+        if (node === null) return new TreeNode(val);
+        /* 1. Find insertion position and insert node */
+        if (val < node.val) node.left = this.#insertHelper(node.left, val);
+        else if (val > node.val)
+            node.right = this.#insertHelper(node.right, val);
+        else return node; // Duplicate node not inserted, return directly
+        this.#updateHeight(node); // Update node height
+        /* 2. Perform rotation operation to restore balance to this subtree */
+        node = this.#rotate(node);
+        // Return root node of subtree
+        return node;
+    }
+
+    /* Remove node */
+    remove(val) {
+        this.root = this.#removeHelper(this.root, val);
+    }
+
+    /* Recursively delete node (helper method) */
+    #removeHelper(node, val) {
+        if (node === null) return null;
+        /* 1. Find node and delete */
+        if (val < node.val) node.left = this.#removeHelper(node.left, val);
+        else if (val > node.val)
+            node.right = this.#removeHelper(node.right, val);
+        else {
+            if (node.left === null || node.right === null) {
+                const child = node.left !== null ? node.left : node.right;
+                // Number of child nodes = 0, delete node directly and return
+                if (child === null) return null;
+                // Number of child nodes = 1, delete node directly
+                else node = child;
+            } else {
+                // Number of child nodes = 2, delete the next node in inorder traversal and replace current node with it
+                let temp = node.right;
+                while (temp.left !== null) {
+                    temp = temp.left;
+                }
+                node.right = this.#removeHelper(node.right, temp.val);
+                node.val = temp.val;
+            }
+        }
+        this.#updateHeight(node); // Update node height
+        /* 2. Perform rotation operation to restore balance to this subtree */
+        node = this.#rotate(node);
+        // Return root node of subtree
+        return node;
+    }
+
+    /* Search node */
+    search(val) {
+        let cur = this.root;
+        // Loop search, exit after passing leaf node
+        while (cur !== null) {
+            // Target node is in cur's right subtree
+            if (cur.val < val) cur = cur.right;
+            // Target node is in cur's left subtree
+            else if (cur.val > val) cur = cur.left;
+            // Found target node, exit loop
+            else break;
+        }
+        // Return target node
+        return cur;
+    }
+}
+
+function testInsert(tree, val) {
+    tree.insert(val);
+    console.log('\nInsert node ' + val + ', AVL tree is');
+    printTree(tree.root);
+}
+
+function testRemove(tree, val) {
+    tree.remove(val);
+    console.log('\nRemove node ' + val + ', AVL tree is');
+    printTree(tree.root);
+}
+
+/* Driver Code */
+/* Please pay attention to how the AVL tree maintains balance after inserting nodes */
+const avlTree = new AVLTree();
+/* Insert node */
+// Delete nodes
+testInsert(avlTree, 1);
+testInsert(avlTree, 2);
+testInsert(avlTree, 3);
+testInsert(avlTree, 4);
+testInsert(avlTree, 5);
+testInsert(avlTree, 8);
+testInsert(avlTree, 7);
+testInsert(avlTree, 9);
+testInsert(avlTree, 10);
+testInsert(avlTree, 6);
+
+/* Please pay attention to how the AVL tree maintains balance after deleting nodes */
+testInsert(avlTree, 7);
+
+/* Remove node */
+// Delete node with degree 1
+testRemove(avlTree, 8); // Delete node with degree 2
+testRemove(avlTree, 5); // Remove node with degree 1
+testRemove(avlTree, 4); // Remove node with degree 2
+
+/* Search node */
+const node = avlTree.search(7);
+console.log('\nFound node object is', node, ', node value = ' + node.val);

en/codes/javascript/chapter_tree/binary_search_tree.js

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+/**
+ * File: binary_search_tree.js
+ * Created Time: 2022-12-04
+ * Author: IsChristina (christinaxia77@foxmail.com)
+ */
+
+const { TreeNode } = require('../modules/TreeNode');
+const { printTree } = require('../modules/PrintUtil');
+
+/* Binary search tree */
+class BinarySearchTree {
+    /* Constructor */
+    constructor() {
+        // Initialize empty tree
+        this.root = null;
+    }
+
+    /* Get binary tree root node */
+    getRoot() {
+        return this.root;
+    }
+
+    /* Search node */
+    search(num) {
+        let cur = this.root;
+        // Loop search, exit after passing leaf node
+        while (cur !== null) {
+            // Target node is in cur's right subtree
+            if (cur.val < num) cur = cur.right;
+            // Target node is in cur's left subtree
+            else if (cur.val > num) cur = cur.left;
+            // Found target node, exit loop
+            else break;
+        }
+        // Return target node
+        return cur;
+    }
+
+    /* Insert node */
+    insert(num) {
+        // If tree is empty, initialize root node
+        if (this.root === null) {
+            this.root = new TreeNode(num);
+            return;
+        }
+        let cur = this.root,
+            pre = null;
+        // Loop search, exit after passing leaf node
+        while (cur !== null) {
+            // Found duplicate node, return directly
+            if (cur.val === num) return;
+            pre = cur;
+            // Insertion position is in cur's right subtree
+            if (cur.val < num) cur = cur.right;
+            // Insertion position is in cur's left subtree
+            else cur = cur.left;
+        }
+        // Insert node
+        const node = new TreeNode(num);
+        if (pre.val < num) pre.right = node;
+        else pre.left = node;
+    }
+
+    /* Remove node */
+    remove(num) {
+        // If tree is empty, return directly
+        if (this.root === null) return;
+        let cur = this.root,
+            pre = null;
+        // Loop search, exit after passing leaf node
+        while (cur !== null) {
+            // Found node to delete, exit loop
+            if (cur.val === num) break;
+            pre = cur;
+            // Node to delete is in cur's right subtree
+            if (cur.val < num) cur = cur.right;
+            // Node to delete is in cur's left subtree
+            else cur = cur.left;
+        }
+        // If no node to delete, return directly
+        if (cur === null) return;
+        // Number of child nodes = 0 or 1
+        if (cur.left === null || cur.right === null) {
+            // When number of child nodes = 0 / 1, child = null / that child node
+            const child = cur.left !== null ? cur.left : cur.right;
+            // Delete node cur
+            if (cur !== this.root) {
+                if (pre.left === cur) pre.left = child;
+                else pre.right = child;
+            } else {
+                // If deleted node is root node, reassign root node
+                this.root = child;
+            }
+        }
+        // Number of child nodes = 2
+        else {
+            // Get next node of cur in inorder traversal
+            let tmp = cur.right;
+            while (tmp.left !== null) {
+                tmp = tmp.left;
+            }
+            // Recursively delete node tmp
+            this.remove(tmp.val);
+            // Replace cur with tmp
+            cur.val = tmp.val;
+        }
+    }
+}
+
+/* Driver Code */
+/* Initialize binary search tree */
+const bst = new BinarySearchTree();
+// Please note that different insertion orders will generate different binary trees, this sequence can generate a perfect binary tree
+const nums = [8, 4, 12, 2, 6, 10, 14, 1, 3, 5, 7, 9, 11, 13, 15];
+for (const num of nums) {
+    bst.insert(num);
+}
+console.log('\nInitialized binary tree is\n');
+printTree(bst.getRoot());
+
+/* Search node */
+const node = bst.search(7);
+console.log('\nFound node object is ' + node + ', node value = ' + node.val);
+
+/* Insert node */
+bst.insert(16);
+console.log('\nAfter inserting node 16, binary tree is\n');
+printTree(bst.getRoot());
+
+/* Remove node */
+bst.remove(1);
+console.log('\nAfter removing node 1, binary tree is\n');
+printTree(bst.getRoot());
+bst.remove(2);
+console.log('\nAfter removing node 2, binary tree is\n');
+printTree(bst.getRoot());
+bst.remove(4);
+console.log('\nAfter removing node 4, binary tree is\n');
+printTree(bst.getRoot());

en/codes/javascript/chapter_tree/binary_tree.js

@@ -0,0 +1,35 @@
+/**
+ * File: binary_tree.js
+ * Created Time: 2022-12-04
+ * Author: IsChristina (christinaxia77@foxmail.com)
+ */
+
+const { TreeNode } = require('../modules/TreeNode');
+const { printTree } = require('../modules/PrintUtil');
+
+/* Initialize binary tree */
+// Initialize nodes
+let n1 = new TreeNode(1),
+    n2 = new TreeNode(2),
+    n3 = new TreeNode(3),
+    n4 = new TreeNode(4),
+    n5 = new TreeNode(5);
+// Build references (pointers) between nodes
+n1.left = n2;
+n1.right = n3;
+n2.left = n4;
+n2.right = n5;
+console.log('\nInitialize binary tree\n');
+printTree(n1);
+
+/* Insert node P between n1 -> n2 */
+const P = new TreeNode(0);
+// Delete node
+n1.left = P;
+P.left = n2;
+console.log('\nAfter inserting node P\n');
+printTree(n1);
+// Remove node P
+n1.left = n2;
+console.log('\nAfter removing node P\n');
+printTree(n1);

en/codes/javascript/chapter_tree/binary_tree_bfs.js

@@ -0,0 +1,34 @@
+/**
+ * File: binary_tree_bfs.js
+ * Created Time: 2022-12-04
+ * Author: IsChristina (christinaxia77@foxmail.com)
+ */
+
+const { arrToTree } = require('../modules/TreeNode');
+const { printTree } = require('../modules/PrintUtil');
+
+/* Level-order traversal */
+function levelOrder(root) {
+    // Initialize queue, add root node
+    const queue = [root];
+    // Initialize a list to save the traversal sequence
+    const list = [];
+    while (queue.length) {
+        let node = queue.shift(); // Dequeue
+        list.push(node.val); // Save node value
+        if (node.left) queue.push(node.left); // Left child node enqueue
+        if (node.right) queue.push(node.right); // Right child node enqueue
+    }
+    return list;
+}
+
+/* Driver Code */
+/* Initialize binary tree */
+// Here we use a function to generate a binary tree directly from an array
+const root = arrToTree([1, 2, 3, 4, 5, 6, 7]);
+console.log('\nInitialize binary tree\n');
+printTree(root);
+
+/* Level-order traversal */
+const list = levelOrder(root);
+console.log('\nLevel-order traversal node print sequence = ' + list);

en/codes/javascript/chapter_tree/binary_tree_dfs.js

@@ -0,0 +1,60 @@
+/**
+ * File: binary_tree_dfs.js
+ * Created Time: 2022-12-04
+ * Author: IsChristina (christinaxia77@foxmail.com)
+ */
+
+const { arrToTree } = require('../modules/TreeNode');
+const { printTree } = require('../modules/PrintUtil');
+
+// Initialize list for storing traversal sequence
+const list = [];
+
+/* Preorder traversal */
+function preOrder(root) {
+    if (root === null) return;
+    // Visit priority: root node -> left subtree -> right subtree
+    list.push(root.val);
+    preOrder(root.left);
+    preOrder(root.right);
+}
+
+/* Inorder traversal */
+function inOrder(root) {
+    if (root === null) return;
+    // Visit priority: left subtree -> root node -> right subtree
+    inOrder(root.left);
+    list.push(root.val);
+    inOrder(root.right);
+}
+
+/* Postorder traversal */
+function postOrder(root) {
+    if (root === null) return;
+    // Visit priority: left subtree -> right subtree -> root node
+    postOrder(root.left);
+    postOrder(root.right);
+    list.push(root.val);
+}
+
+/* Driver Code */
+/* Initialize binary tree */
+// Here we use a function to generate a binary tree directly from an array
+const root = arrToTree([1, 2, 3, 4, 5, 6, 7]);
+console.log('\nInitialize binary tree\n');
+printTree(root);
+
+/* Preorder traversal */
+list.length = 0;
+preOrder(root);
+console.log('\nPreorder traversal node print sequence = ' + list);
+
+/* Inorder traversal */
+list.length = 0;
+inOrder(root);
+console.log('\nInorder traversal node print sequence = ' + list);
+
+/* Postorder traversal */
+list.length = 0;
+postOrder(root);
+console.log('\nPostorder traversal node print sequence = ' + list);