80 lines
3.2 KiB
Markdown
80 lines
3.2 KiB
Markdown
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---
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id: 587d825a367417b2b2512c88
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title: Reverse a Doubly Linked List
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localeTitle: Invertir una lista doblemente vinculada
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challengeType: 1
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---
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## Description
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<section id='description'>
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Creemos un método más para nuestra lista doblemente enlazada llamada reversa que invierte la lista en su lugar. Una vez que se ejecuta el método, la cabeza debe apuntar a la cola anterior y la cola debe apuntar a la cabeza anterior. Ahora, si recorremos la lista de principio a fin, deberíamos encontrar los nodos en orden inverso en comparación con la lista original. Intentar revertir una lista vacía debe devolver nulo.
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</section>
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## Instructions
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<section id='instructions'>
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: La estructura de datos DoublyLinkedList existe.
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testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; return (typeof test == "object")})(), "The DoublyLinkedList data structure exists.");'
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- text: DoublyLinkedList tiene un método llamado agregar.
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testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; if (test.add == undefined) { return false; }; return (typeof test.add == "function")})(), "The DoublyLinkedList has a method called add.");'
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- text: El DoublyLinkedList tiene un método llamado reversa.
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testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; if (test.reverse == undefined) { return false; }; return (typeof test.reverse == "function")})(), "The DoublyLinkedList has a method called reverse.");'
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- text: Invertir una lista vacía devuelve nulo.
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testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; return (test.reverse() == null); })(), "Reversing an empty list returns null.");'
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- text: El método inverso invierte la lista.
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testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; test.add(58); test.add(61); test.add(32); test.reverse(); return (test.print().join("") == "326158"); })(), "The reverse method reverses the list.");'
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- text: Las referencias siguientes y anteriores se mantienen correctamente cuando se invierte una lista.
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testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; test.add(11); test.add(22); test.add(33); test.reverse(); return (test.printReverse().join("") == "112233"); })(), "The next and previous references are correctly maintained when a list is reversed.");'
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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var Node = function(data, prev) {
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this.data = data;
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this.prev = prev;
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this.next = null;
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};
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var DoublyLinkedList = function() {
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this.head = null;
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this.tail = null;
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// change code below this line
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// change code above this line
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};
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```
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</div>
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### After Test
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<div id='js-teardown'>
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```js
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console.info('after the test');
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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// solution required
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```
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</section>
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