Oliver Eyton-Williams ee1e8abd87

feat(curriculum): restore seed + solution to Chinese (#40683 )

* 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>

2021-01-12 19:31:00 -07:00

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id, title, challengeType, videoUrl, dashedName

id	title	challengeType	videoUrl	dashedName
587d8252367417b2b2512c67	在链接列表中的特定索引处添加元素	1		add-elements-at-a-specific-index-in-a-linked-list

--description--

让我们创建一个addAt（index，element）方法，在给定的索引处添加一个元素。就像我们如何删除给定索引处的元素一样，我们需要在遍历链表时跟踪currentIndex。当currentIndex与给定索引匹配时，我们需要重新分配上一个节点的下一个属性以引用新添加的节点。并且新节点应该引用currentIndex中的下一个节点。回到康加线的例子，一个新人想加入这条线，但他想加入中间。你处于中间位置，所以你要把手从你前面的人身上移开。新人走过去，把手放在你曾经牵过手的那个人身上，现在你已经掌握了新人。说明创建addAt（index，element）方法，该方法在给定索引处添加元素。如果无法添加元素，则返回false。注意请记住检查给定索引是否为负数或者是否长于链接列表的长度。

--hints--

当给定索引为0时， addAt方法应重新分配head到新节点。

assert(
  (function () {
    var test = new LinkedList();
    test.add('cat');
    test.add('dog');
    test.addAt(0, 'cat');
    return test.head().element === 'cat';
  })()
);

对于添加到链接列表的每个新节点， addAt方法应该将链表的长度增加一。

assert(
  (function () {
    var test = new LinkedList();
    test.add('cat');
    test.add('dog');
    test.addAt(0, 'cat');
    return test.size() === 3;
  })()
);

如果无法添加节点，则addAt方法应返回false 。

assert(
  (function () {
    var test = new LinkedList();
    test.add('cat');
    test.add('dog');
    return test.addAt(4, 'cat') === false;
  })()
);

--seed--

--seed-contents--

function LinkedList() {
  var length = 0;
  var head = null;

  var Node = function(element) {
    this.element = element;
    this.next = null;
  };

  this.size = function() {
    return length;
  };

  this.head = function() {
    return head;
  };

  this.add = function(element) {
    var node = new Node(element);
    if (head === null) {
      head = node;
    } else {
      var currentNode = head;

      while (currentNode.next) {
        currentNode = currentNode.next;
      }

      currentNode.next = node;
    }
    length++;
  };

  // Only change code below this line

  // Only change code above this line
}

--solutions--

function LinkedList() {
  var length = 0;
  var head = null;

  var Node = function(element){
    this.element = element;
    this.next = null;
  };

  this.size = function(){
    return length;
  };

  this.head = function(){
    return head;
  };

  this.add = function(element){
    var node = new Node(element);
    if (head === null){
        head = node;
    } else {
      var currentNode = head;

      while (currentNode.next) {
        currentNode = currentNode.next;
      }

      currentNode.next = node;
    }
    length++;
  };
  this.addAt = function (index, element) {
    if (index > length || index < 0) {
      return false;
    }
    var newNode = new Node(element);
    var currentNode = head;
    if (index === 0) {
      head = newNode;
    } else {
      var previousNode = null;
      var i = 0;
      while (currentNode && i < index) {
        previousNode = currentNode;
        currentNode = currentNode.next;
        i++;
      }
      previousNode.next = newNode;
    }
    newNode.next = currentNode;
    length++;
  }
}

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