在ANSI C动态列表？ [英] Dynamic list in ANSI C?

问题描述

我说的对的思维创造用C在运行时它生长名单的唯一办法，就是用链表？

Am i right in thinking the only way to create a list which grows during run time in C, is to use a linked list?

推荐答案

链表是单向的。它有 O（1）插入（假设你在插入点是已经）和删除，但 O（N） N 'th元素查找。

Linked list is one way. It has O(1) insertion (assuming you're already at the insertion point) and deletion, but O(n) n'th element lookup.

调整与的malloc 是另外一个动态分配的数组。它有 O（1） N 'th元素查找，但<​​code> O（N）插入（由于有复制的插入点毕竟后面的元素，并在可能的所有元素的realloc ），并删除。

Resizing a dynamically allocated array with malloc is another. It has O(1) n'th element lookup but O(n) insertion (due to having to copy all later elements after the insertion point, and possibly all elements on realloc) and deletion.

如果你真的很担心针对这两项操作的表现，我会去与某种自我平衡的树结构。你一定能达到 O（log n）的的查找，插入和删除。而对于所有的实际目的，如果对象在主内存中，为log N 由32或64界和 O（log n）的可能会成为 O（1）。

If you're really worried about performance for both these operations, I would go with some sort of self-balancing tree structure. You can surely attain O(log n)for lookup, insertion, and deletion. And for all practical purposes if objects are in main memory, log n is bounded by 32 or 64 and O(log n) might as well be O(1).

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