feat: add linkedlist_stack in js

codes/javascript/chapter_stack_and_queue/linkedlist_stack.js

@@ -0,0 +1,93 @@
+/**#stkSize
+ * File: linkedlist_queue.js
+ * Created Time: 2022-12-22
+ * Author: S-N-O-R-L-A-X (snorlax.xu@outlook.com)
+ */
+
+const ListNode = require("../include/ListNode");
+
+/* 基于链表实现的栈 */
+class LinkedListStack {
+    #stackPeek;  // 将头结点作为栈顶
+    #stkSize = 0;   // 栈的长度
+
+    constructor() {
+        this.#stackPeek = null;
+    }
+
+    /* 获取栈的长度 */
+    get size() {
+        return this.#stkSize;
+    }
+
+    /* 判断栈是否为空 */
+    isEmpty() {
+        return this.size == 0;
+    }
+
+    /* 入栈 */
+    push(num) {
+        const node = new ListNode(num);
+        node.next = this.#stackPeek;
+        this.#stackPeek = node;
+        this.#stkSize++;
+    }
+
+    /* 出栈 */
+    pop() {
+        const num = this.peek();
+        if (!this.#stackPeek) {
+            throw new Error("栈为空！");
+        }
+        this.#stackPeek = this.#stackPeek.next;
+        this.#stkSize--;
+        return num;
+    }
+
+    /* 访问栈顶元素 */
+    peek() {
+        if (!this.#stackPeek) {
+            throw new Error("栈为空！");
+        }
+        return this.#stackPeek.val;
+    }
+
+    /* 将 List 转化为 Array 并返回 */
+    toArray() {
+        let node = this.#stackPeek;
+        const res = new Array(this.size);
+        for (let i = res.length - 1; i >= 0; i--) {
+            res[i] = node.val;
+            node = node.next;
+        }
+        return res;
+    }
+}
+
+
+/* 初始化栈 */
+const stack = new LinkedListStack();
+
+/* 元素入栈 */
+stack.push(1);
+stack.push(3);
+stack.push(2);
+stack.push(5);
+stack.push(4);
+console.log("栈 stack = " + stack.toArray());
+
+/* 访问栈顶元素 */
+const peek = stack.peek();
+console.log("栈顶元素 peek = " + peek);
+
+/* 元素出栈 */
+const pop = stack.pop();
+console.log("出栈元素 pop = " + pop + "，出栈后 stack = " + stack.toArray());
+
+/* 获取栈的长度 */
+const size = stack.size;
+console.log("栈的长度 size = " + size);
+
+/* 判断是否为空 */
+const isEmpty = stack.isEmpty();
+console.log("栈是否为空 = " + isEmpty);