ee1e8abd87
* feat(tools): add seed/solution restore script * chore(curriculum): remove empty sections' markers * chore(curriculum): add seed + solution to Chinese * chore: remove old formatter * fix: update getChallenges parse translated challenges separately, without reference to the source * chore(curriculum): add dashedName to English * chore(curriculum): add dashedName to Chinese * refactor: remove unused challenge property 'name' * fix: relax dashedName requirement * fix: stray tag Remove stray `pre` tag from challenge file. Signed-off-by: nhcarrigan <nhcarrigan@gmail.com> Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
161 lines
3.1 KiB
Markdown
161 lines
3.1 KiB
Markdown
---
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id: 587d8250367417b2b2512c5f
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title: 创建一个堆栈类
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challengeType: 1
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videoUrl: ''
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dashedName: create-a-stack-class
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---
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# --description--
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在上一节中，我们讨论了堆栈是什么以及如何使用数组来表示堆栈。在本节中，我们将创建自己的堆栈类。虽然您可以使用数组来创建堆栈，但有时最好限制我们对堆栈的控制量。除了`push`和`pop`方法之外，堆栈还有其他有用的方法。让我们为我们的堆栈类添加一个`peek` ， `isEmpty`和`clear`方法。说明编写一个`push`方法，将元素推送到堆栈顶部，一个`pop`方法删除堆栈顶部的元素，一个`peek`堆栈中第一个元素的`peek`方法，一个`isEmpty`方法，用于检查是否存在stack是空的，是一个`clear`堆栈中所有元素的方法。通常堆栈没有这个，但我们添加了一个控制台记录集合的`print`助手方法。
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# --hints--
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你的`Stack`类应该有一个`push`方法。
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```js
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assert(
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(function () {
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var test = new Stack();
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return typeof test.push === 'function';
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})()
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);
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```
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你的`Stack`类应该有一个`pop`方法。
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```js
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assert(
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(function () {
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var test = new Stack();
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return typeof test.pop === 'function';
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})()
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);
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```
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你的`Stack`类应该有一个`peek`方法。
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```js
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assert(
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(function () {
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var test = new Stack();
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return typeof test.peek === 'function';
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})()
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);
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```
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您的`Stack`类应该有一个`isEmpty`方法。
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```js
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assert(
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(function () {
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var test = new Stack();
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return typeof test.isEmpty === 'function';
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})()
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);
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```
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你的`Stack`类应该有一个`clear`方法。
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```js
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assert(
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(function () {
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var test = new Stack();
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return typeof test.clear === 'function';
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})()
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);
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```
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`peek`方法应该返回堆栈的顶部元素
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```js
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assert(
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(function () {
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var test = new Stack();
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test.push('CS50');
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return test.peek() === 'CS50';
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})()
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);
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```
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`pop`方法应该删除并返回堆栈的顶部元素
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```js
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assert(
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(function () {
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var test = new Stack();
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test.push('CS50');
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return test.pop() === 'CS50';
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})()
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);
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```
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如果堆栈不包含任何元素，则`isEmpty`方法应返回true
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```js
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assert(
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(function () {
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var test = new Stack();
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return test.isEmpty();
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})()
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);
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```
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`clear`方法应该从堆栈中删除所有元素
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```js
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assert(
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(function () {
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var test = new Stack();
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test.push('CS50');
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test.clear();
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return test.isEmpty();
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})()
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);
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```
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# --seed--
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## --seed-contents--
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```js
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function Stack() {
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var collection = [];
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this.print = function() {
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console.log(collection);
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};
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// Only change code below this line
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// Only change code above this line
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}
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```
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# --solutions--
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```js
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class Stack {
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constructor() {
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this.collection = [];
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}
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print() {
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console.log(this.collection);
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}
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push(val) {
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this.collection.push(val);
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}
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pop() {
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return this.collection.pop();
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}
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peek() {
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return this.collection[this.collection.length - 1];
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}
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isEmpty() {
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return this.collection.length === 0;
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}
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clear() {
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return (this.collection.length = 0);
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}
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}
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```
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