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.

在数组中，您有权限在O(1)时间内访问任何元素。所以它适用于二进制搜索、快速排序等操作。链表则适合于插入删除，因为它在O(1)时间内。两者都有优点和缺点，选择一种而不是另一种归结为您想要实现什么。

—更大的问题是，我们能有一个两者的混合体吗?类似于python和perl实现的列表。

这里有一个快速的方法:移除物品更快。

对我来说是这样的，

Access Linked Lists allow only sequential access to elements. Thus the algorithmic complexities is order of O(n) Arrays allow random access to its elements and thus the complexity is order of O(1) Storage Linked lists require an extra storage for references. This makes them impractical for lists of small data items such as characters or boolean values. Arrays do not need an extra storage to point to next data item. Each element can be accessed via indexes. Size The size of Linked lists are dynamic by nature. The size of array is restricted to declaration. Insertion/Deletion Elements can be inserted and deleted in linked lists indefinitely. Insertion/Deletion of values in arrays are very expensive. It requires memory reallocation.

维基百科上有很好的章节介绍了它们的区别。

Linked lists have several advantages over arrays. Elements can be inserted into linked lists indefinitely, while an array will eventually either fill up or need to be resized, an expensive operation that may not even be possible if memory is fragmented. Similarly, an array from which many elements are removed may become wastefully empty or need to be made smaller. On the other hand, arrays allow random access, while linked lists allow only sequential access to elements. Singly-linked lists, in fact, can only be traversed in one direction. This makes linked lists unsuitable for applications where it's useful to look up an element by its index quickly, such as heapsort. Sequential access on arrays is also faster than on linked lists on many machines due to locality of reference and data caches. Linked lists receive almost no benefit from the cache. Another disadvantage of linked lists is the extra storage needed for references, which often makes them impractical for lists of small data items such as characters or boolean values. It can also be slow, and with a naïve allocator, wasteful, to allocate memory separately for each new element, a problem generally solved using memory pools.

http://en.wikipedia.org/wiki/Linked_list

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。