Add JavaScript and TypeScript code and docs for Section Space Complexity

codes/javascript/chapter_array_and_linkedlist/linked_list.js

@@ -4,8 +4,8 @@
  * Author: IsChristina (christinaxia77@foxmail.com), Justin (xiefahit@gmail.com)
  */
 
-const PrintUtil = require("../include/PrintUtil");
-const ListNode = require("../include/ListNode");
+const { printLinkedList } = require("../include/PrintUtil");
+const { ListNode } = require("../include/ListNode");
 
 /* 在链表的结点 n0 之后插入结点 P */
 function insert(n0, P) {
@@ -62,17 +62,17 @@ n1.next = n2;
 n2.next = n3;
 n3.next = n4;
 console.log("初始化的链表为");
-PrintUtil.printLinkedList(n0);
+printLinkedList(n0);
 
 /* 插入结点 */
 insert(n0, new ListNode(0));
 console.log("插入结点后的链表为");
-PrintUtil.printLinkedList(n0);
+printLinkedList(n0);
 
 /* 删除结点 */
 remove(n0);
 console.log("删除结点后的链表为");
-PrintUtil.printLinkedList(n0);
+printLinkedList(n0);
 
 /* 访问结点 */
 const node = access(n0, 3);

codes/javascript/chapter_computational_complexity/space_complexity.js

@@ -0,0 +1,101 @@
+/**
+ * File: space_complexity.js
+ * Created Time: 2023-02-05
+ * Author: Justin (xiefahit@gmail.com)
+ */
+
+const { ListNode } = require('../include/ListNode');
+const { TreeNode } = require('../include/TreeNode');
+const { printTree } = require('../include/PrintUtil');
+
+/* 函数 */
+function constFunc() {
+    // do something
+    return 0;
+}
+
+/* 常数阶 */
+function constant(n) {
+    // 常量、变量、对象占用 O(1) 空间
+    const a = 0;
+    const b = 0;
+    const nums = new Array(10000);
+    const node = new ListNode(0);
+    // 循环中的变量占用 O(1) 空间
+    for (let i = 0; i < n; i++) {
+        const c = 0;
+    }
+    // 循环中的函数占用 O(1) 空间
+    for (let i = 0; i < n; i++) {
+        constFunc();
+    }
+}
+
+/* 线性阶 */
+function linear(n) {
+    // 长度为 n 的数组占用 O(n) 空间
+    const nums = new Array(n);
+    // 长度为 n 的列表占用 O(n) 空间
+    const nodes = [];
+    for (let i = 0; i < n; i++) {
+        nodes.push(new ListNode(i));
+    }
+    // 长度为 n 的哈希表占用 O(n) 空间
+    const map = new Map();
+    for (let i = 0; i < n; i++) {
+        map.set(i, i.toString());
+    }
+}
+
+/* 线性阶（递归实现） */
+function linearRecur(n) {
+    console.log(`递归 n = ${n}`);
+    if (n === 1) return;
+    linearRecur(n - 1);
+}
+
+/* 平方阶 */
+function quadratic(n) {
+    // 矩阵占用 O(n^2) 空间
+    const numMatrix = Array(n).fill(null).map(() => Array(n).fill(null));
+    // 二维列表占用 O(n^2) 空间
+    const numList = [];
+    for (let i = 0; i < n; i++) {
+        const tmp = [];
+        for (let j = 0; j < n; j++) {
+            tmp.push(0);
+        }
+        numList.push(tmp);
+    }
+}
+
+/* 平方阶（递归实现） */
+function quadraticRecur(n) {
+    if (n <= 0) return 0;
+    const nums = new Array(n);
+    console.log(`递归 n = ${n} 中的 nums 长度 = ${nums.length}`);
+    return quadraticRecur(n - 1);
+}
+
+/* 指数阶（建立满二叉树） */
+function buildTree(n) {
+    if (n === 0) return null;
+    const root = new TreeNode(0);
+    root.left = buildTree(n - 1);
+    root.right = buildTree(n - 1);
+    return root;
+}
+
+/* Driver Code */
+const n = 5;
+// 常数阶
+constant(n);
+// 线性阶
+linear(n);
+linearRecur(n);
+// 平方阶
+quadratic(n);
+quadraticRecur(n);
+// 指数阶
+const root = buildTree(n);
+printTree(root);

codes/javascript/chapter_computational_complexity/worst_best_time_complexity.js

@@ -13,8 +13,8 @@ function randomNumbers(n) {
     }
     // 随机打乱数组元素
     for (let i = 0; i < n; i++) {
-        let r = Math.floor(Math.random() * (i + 1));
-        let temp = nums[i];
+        const r = Math.floor(Math.random() * (i + 1));
+        const temp = nums[i];
         nums[i] = nums[r];
         nums[r] = temp;
     }
@@ -34,14 +34,12 @@ function findOne(nums) {
 }
 
 /* Driver Code */
-function main() {
-    for (let i = 0; i < 10; i++) {
-        let n = 100;
-        let nums = randomNumbers(n);
-        let index = findOne(nums);
-        console.log(
-            "\n数组 [ 1, 2, ..., n ] 被打乱后 = [" + nums.join(", ") + "]"
-        );
-        console.log("数字 1 的索引为 " + index);
-    }
+for (let i = 0; i < 10; i++) {
+    const n = 100;
+    const nums = randomNumbers(n);
+    const index = findOne(nums);
+    console.log(
+        "\n数组 [ 1, 2, ..., n ] 被打乱后 = [" + nums.join(", ") + "]"
+    );
+    console.log("数字 1 的索引为 " + index);
 }

codes/javascript/chapter_searching/hashing_search.js

@@ -4,48 +4,42 @@
  * Author: Zhuo Qinyue (1403450829@qq.com)
  */
 
-const PrintUtil = require("../include/PrintUtil");
-const ListNode = require("../include/ListNode");
-
+const { ListNode, arrToLinkedList } = require("../include/ListNode");
 
 /* 哈希查找（数组） */
-function hashingSearch(map, target) {
+function hashingSearchArray(map, target) {
     // 哈希表的 key: 目标元素，value: 索引
     // 若哈希表中无此 key ，返回 -1
     return map.has(target) ? map.get(target) : -1;
 }
 
 /* 哈希查找（链表） */
-function hashingSearch1(map, target) {
+function hashingSearchLinkedList(map, target) {
     // 哈希表的 key: 目标结点值，value: 结点对象
     // 若哈希表中无此 key ，返回 null
     return map.has(target) ? map.get(target) : null;
 }
 
-function main() {
-    const target = 3;
-
-    /* 哈希查找（数组） */
-    const nums = [1, 5, 3, 2, 4, 7, 5, 9, 10, 8];
-    // 初始化哈希表
-    const map = new Map();
-    for (let i = 0; i < nums.length; i++) {
-      map.set(nums[i], i);  // key: 元素，value: 索引
-    }
-    const index = hashingSearch(map, target);
-    console.log("目标元素 3 的索引 = " + index);
+/* Driver Code */
+const target = 3;
 
-    /* 哈希查找（链表） */
-    let head = new ListNode().arrToLinkedList(nums)
-    // 初始化哈希表
-    const map1 = new Map();
-    while (head != null) {
-      map1.set(head.val, head);  // key: 结点值，value: 结点
-      head = head.next;
-    }
-    const node = hashingSearch1(map1, target);
-    console.log("目标结点值 3 的对应结点对象为" );
-    PrintUtil.printLinkedList(node);
+/* 哈希查找（数组） */
+const nums = [1, 5, 3, 2, 4, 7, 5, 9, 10, 8];
+// 初始化哈希表
+const map = new Map();
+for (let i = 0; i < nums.length; i++) {
+    map.set(nums[i], i);  // key: 元素，value: 索引
 }
+const index = hashingSearchArray(map, target);
+console.log("目标元素 3 的索引 = " + index);
 
-main();
+/* 哈希查找（链表） */
+let head = arrToLinkedList(nums)
+// 初始化哈希表
+const map1 = new Map();
+while (head != null) {
+    map1.set(head.val, head);  // key: 结点值，value: 结点
+    head = head.next;
+}
+const node = hashingSearchLinkedList(map1, target);
+console.log("目标结点值 3 的对应结点对象为", node);

codes/javascript/chapter_searching/linear_search.js

@@ -4,7 +4,7 @@
  * Author: JoseHung (szhong@link.cuhk.edu.hk)
  */
 
-const ListNode = require("../include/ListNode");
+const { ListNode, arrToLinkedList } = require("../include/ListNode");
 
 /* 线性查找（数组） */
 function linearSearchArray(nums, target) {
@@ -34,15 +34,14 @@ function linearSearchLinkedList(head, target) {
 }
 
 /* Driver Code */
-var target = 3;
+const target = 3;
 
 /* 在数组中执行线性查找 */
-var nums = [1, 5, 3, 2, 4, 7, 5, 9, 10, 8];
-var index = linearSearchArray(nums, target);
+const nums = [1, 5, 3, 2, 4, 7, 5, 9, 10, 8];
+const index = linearSearchArray(nums, target);
 console.log("目标元素 3 的索引 = " + index);
 
 /* 在链表中执行线性查找 */
-var linkedList = new ListNode();
-var head = linkedList.arrToLinkedList(nums);
-var node = linearSearchLinkedList(head, target);
-console.log("目标结点值 3 的对应结点对象为 " + node);
+const head = arrToLinkedList(nums);
+const node = linearSearchLinkedList(head, target);
+console.log("目标结点值 3 的对应结点对象为 ", node);

codes/javascript/chapter_stack_and_queue/array_queue.js

@@ -31,8 +31,10 @@ class ArrayQueue {
 
     /* 入队 */
     push(num) {
-        if (this.size == this.capacity)
-            throw new Error("队列已满");
+        if (this.size == this.capacity) {
+            console.log("队列已满");
+            return;
+        }
         // 计算尾指针，指向队尾索引 + 1
         // 通过取余操作，实现 rear 越过数组尾部后回到头部
         const rear = (this.#front + this.size) % this.capacity;

codes/javascript/chapter_stack_and_queue/linkedlist_queue.js

@@ -4,7 +4,7 @@
  * Author: S-N-O-R-L-A-X (snorlax.xu@outlook.com)
  */
 
-const ListNode = require("../include/ListNode");
+const { ListNode } = require("../include/ListNode");
 
 /* 基于链表实现的队列 */
 class LinkedListQueue {

codes/javascript/chapter_stack_and_queue/linkedlist_stack.js

@@ -4,7 +4,7 @@
  * Author: S-N-O-R-L-A-X (snorlax.xu@outlook.com)
  */
 
-const ListNode = require("../include/ListNode");
+const { ListNode } = require("../include/ListNode");
 
 /* 基于链表实现的栈 */
 class LinkedListStack {

codes/javascript/include/ListNode.js

@@ -11,37 +11,41 @@ class ListNode {
     val;
     next;
     constructor(val, next) {
-        this.val = (val === undefined ? 0 : val); 
-        this.next = (next === undefined ? null : next); 
+        this.val = (val === undefined ? 0 : val);
+        this.next = (next === undefined ? null : next);
     }
-
-    /**
-     * Generate a linked list with an array
-     * @param arr
-     * @return
-     */
-    arrToLinkedList(arr) {
-        const dum = new ListNode(0);
-        let head = dum;
-        for (const val of arr) {
-            head.next = new ListNode(val);
-            head = head.next;
-        }
-        return dum.next;
+}
+
+/**
+ * Generate a linked list with an array
+ * @param arr
+ * @return
+ */
+function arrToLinkedList(arr) {
+    const dum = new ListNode(0);
+    let head = dum;
+    for (const val of arr) {
+        head.next = new ListNode(val);
+        head = head.next;
     }
+    return dum.next;
+}
 
-    /**
-     * Get a list node with specific value from a linked list
-     * @param head
-     * @param val
-     * @return
-     */
-    getListNode(head, val) {
-        while (head !== null && head.val !== val) {
-            head = head.next;
-        }
-        return head;
+/**
+ * Get a list node with specific value from a linked list
+ * @param head
+ * @param val
+ * @return
+ */
+function getListNode(head, val) {
+    while (head !== null && head.val !== val) {
+        head = head.next;
     }
+    return head;
 }
 
-module.exports = ListNode
+module.exports = {
+    ListNode,
+    arrToLinkedList,
+    getListNode
+};