Fix array queue.

codes/typescript/chapter_stack_and_queue/array_queue.ts

@@ -4,49 +4,50 @@
  * Author: S-N-O-R-L-A-X (snorlax.xu@outlook.com)
  */
 
-
 /* 基于环形数组实现的队列 */
 class ArrayQueue {
-    private queue: number[];     // 用于存储队列元素的数组
-    private front: number = 0;  // 头指针，指向队首
-    private rear: number = 0;   // 尾指针，指向队尾 + 1
-    private CAPACITY: number = 1e5;
+    private nums: number[];  // 用于存储队列元素的数组
+    private front: number;   // 队首指针，指向队首元素
+    private queSize: number; // 队列长度
 
-    constructor(capacity?: number) {
-        this.queue = new Array<number>(capacity ?? this.CAPACITY);
+    constructor(capacity: number) {
+        this.nums = new Array<number>(capacity);
+        this.front = this.queSize = 0;
     }
 
     /* 获取队列的容量 */
     get capacity(): number {
-        return this.queue.length;
+        return this.nums.length;
     }
 
     /* 获取队列的长度 */
     get size(): number {
-        // 由于将数组看作为环形，可能 rear < front ，因此需要取余数
-        return (this.capacity + this.rear - this.front) % this.capacity;
+        return this.queSize;
     }
 
     /* 判断队列是否为空 */
     empty(): boolean {
-        return this.rear - this.front == 0;
+        return this.queSize == 0;
     }
 
     /* 入队 */
     offer(num: number): void {
         if (this.size == this.capacity)
             throw new Error("队列已满");
+        // 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.queSize) % this.capacity;
         // 尾结点后添加 num
-        this.queue[this.rear] = num;
-        // 尾指针向后移动一位，越过尾部后返回到数组头部
-        this.rear = (this.rear + 1) % this.capacity;
+        this.nums[rear] = num;
+        this.queSize++;
     }
 
     /* 出队 */
     poll(): number {
         const num = this.peek();
-        // 队头指针向后移动一位，若越过尾部则返回到数组头部
+        // 队首指针向后移动一位，若越过尾部则返回到数组头部
         this.front = (this.front + 1) % this.capacity;
+        this.queSize--;
         return num;
     }
 
@@ -54,17 +55,15 @@ class ArrayQueue {
     peek(): number {
         if (this.empty())
             throw new Error("队列为空");
-        return this.queue[this.front];
+        return this.nums[this.front];
     }
 
     /* 返回 Array */
     toArray(): number[] {
-        const siz = this.size;
-        const cap = this.capacity;
         // 仅转换有效长度范围内的列表元素
-        const arr = new Array(siz);
-        for (let i = 0, j = this.front; i < siz; i++, j++) {
-            arr[i] = this.queue[j % cap];
+        const arr = new Array(this.size);
+        for (let i = 0, j = this.front; i < this.size; i++, j++) {
+            arr[i] = this.nums[j % this.capacity];
         }
         return arr;
     }
@@ -80,8 +79,7 @@ queue.offer(3);
 queue.offer(2);
 queue.offer(5);
 queue.offer(4);
-console.log("队列 queue = ");
-console.log(queue.toArray());
+console.log("队列 queue =", queue.toArray());
 
 /* 访问队首元素 */
 const peek = queue.peek();
@@ -89,8 +87,7 @@ console.log("队首元素 peek = " + peek);
 
 /* 元素出队 */
 const poll = queue.poll();
-console.log("出队元素 poll = " + poll + "，出队后 queue = ");
-console.log(queue.toArray());
+console.log("出队元素 poll = " + poll + "，出队后 queue =", queue.toArray());
 
 /* 获取队列的长度 */
 const size = queue.size;
@@ -104,8 +101,8 @@ console.log("队列是否为空 = " + empty);
 for (let i = 0; i < 10; i++) {
     queue.offer(i);
     queue.poll();
-    console.log("第 " + i + " 轮入队 + 出队后 queue = ");
+    console.log("第 " + i + " 轮入队 + 出队后 queue =", queue.toArray());
     console.log(queue.toArray());
 }
 
-export { };
+export { };

codes/typescript/module/PrintUtil.ts

@@ -7,16 +7,6 @@
 import ListNode from './ListNode';
 import { TreeNode } from './TreeNode';
 
-class Trunk {
-    prev: Trunk | null;
-    str: string;
-
-    constructor(prev: Trunk | null, str: string) {
-        this.prev = prev;
-        this.str = str;
-    }
-}
-
 /**
  * Print a linked list
  * @param head
@@ -30,6 +20,16 @@ function printLinkedList(head: ListNode | null): void {
     console.log(list.join(' -> '));
 }
 
+class Trunk {
+    prev: Trunk | null;
+    str: string;
+
+    constructor(prev: Trunk | null, str: string) {
+        this.prev = prev;
+        this.str = str;
+    }
+}
+
 /**
  * The interface of the tree printer
  * This tree printer is borrowed from TECHIE DELIGHT