假设您有一个有序集，您还想通过添加和删除元素来修改它。此外，您需要能够以这样的方式保留对元素的引用，以便稍后可以获得前一个或下一个元素。例如，一本书中的待办事项列表或一组段落。

首先，我们应该注意到，如果您想在集合本身之外保留对对象的引用，那么您可能最终会将指针存储在数组中，而不是存储对象本身。否则你将无法插入到数组中-如果对象嵌入到数组中，它们将在插入期间移动，并且任何指向它们的指针都将无效。数组下标也是如此。

您的第一个问题，正如您自己所注意到的，是插入链表允许插入O(1)，但数组通常需要O(n)。这个问题可以部分克服——可以创建一种数据结构，提供类似数组的按顺序访问接口，其中读和写在最坏的情况下都是对数的。

Your second, and more severe problem is that given an element finding next element is O(n). If the set was not modified you could retain the index of the element as the reference instead of the pointer thus making find-next an O(1) operation, but as it is all you have is a pointer to the object itself and no way to determine its current index in the array other than by scanning the entire "array". This is an insurmountable problem for arrays - even if you can optimized insertions, there is nothing you can do to optimize find-next type operation.

为什么有人想要使用链表而不是数组?

这只是一个原因——如果你需要一个链表数据结构，而你所使用的编程语言不支持指针。

While many of you have touched upon major adv./dis of linked list vs array, most of the comparisons are how one is better/ worse than the other.Eg. you can do random access in array but not possible in linked list and others. However, this is assuming link lists and array are going to be applied in a similar application. However a correct answer should be how link list would be preferred over array and vice-versa in a particular application deployment. Suppose you want to implement a dictionary application, what would you use ? Array : mmm it would allow easy retrieval through binary search and other search algo .. but lets think how link list can be better..Say you want to search "Blob" in dictionary. Would it make sense to have a link list of A->B->C->D---->Z and then each list element also pointing to an array or another list of all words starting with that letter ..

A -> B -> C -> ...Z
|    |    |
|    |    [Cat, Cave]
|    [Banana, Blob]
[Adam, Apple]

Now is the above approach better or a flat array of [Adam,Apple,Banana,Blob,Cat,Cave] ? Would it even be possible with array ? So a major advantage of link list is you can have an element not just pointing to the next element but also to some other link list/array/ heap/ or any other memory location. Array is a one flat contigous memory sliced into blocks size of the element it is going to store.. Link list on the other hand is a chunks of non-contigous memory units (can be any size and can store anything) and pointing to each other the way you want. Similarly lets say you are making a USB drive. Now would you like files to be saved as any array or as a link list ? I think you get the idea what I am pointing to :)

为什么是链表而不是数组?有些人已经说过，插入和删除的速度更快。

但也许我们不需要生活在两者的限制下，同时获得两者的优点……是吗?

对于数组删除，您可以使用'Deleted'字节来表示一行已被删除的事实，因此不再需要重新组织数组。为了减轻插入或快速更改数据的负担，可以使用链表。然后，在引用它们的时候，让你的逻辑先搜索一个，再搜索另一个。因此，将它们结合使用可以使您获得两者的最佳效果。

If you have a really large array, you could combine it with another, much smaller array or linked list where the smaller one hold thes 20, 50, 100 most recently used items. If the one needed is not in the shorter linked list or array, you go to the large array. If found there, you can then add it to the smaller linked list/array on the presumption that 'things most recently used are most likey to be re-used' ( and yes, possibly bumping the least recently used item from the list ). Which is true in many cases and solved a problem I had to tackle in an .ASP security permissions checking module, with ease, elegance, and impressive speed.

当集合不断增加和减少时，链表尤其有用。例如，很难想象尝试使用数组实现一个Queue(添加到末尾，从前面删除)—您将花费所有时间向下移动内容。另一方面，对于链表来说，这是微不足道的。

合并两个链表(特别是两个双链表)比合并两个数组快得多(假设合并是破坏性的)。前者取O(1)，后者取O(n)。

编辑:澄清一下，我在这里指的是无序意义上的“合并”，而不是归并排序。也许"串联"这个词更合适。