List是双链表，所以很容易插入和删除一个元素。我们只需要改变这几个指针，而在向量中如果我们想在中间插入一个元素那么它后面的每个元素都要移动一个下标。此外，如果向量的大小已满，那么它必须首先增加它的大小。所以这是一个昂贵的手术。 因此，在这种情况下，只要需要更频繁地执行插入和删除操作，就应该使用案例列表。

当你想在容器之间移动对象时，你可以使用list::splice。

例如，一个图划分算法可以将常数数量的对象递归地划分到数量不断增加的容器中。对象应该初始化一次，并始终保持在内存中的相同位置。通过重新链接来重新排列比重新分配要快得多。

Edit: as libraries prepare to implement C++0x, the general case of splicing a subsequence into a list is becoming linear complexity with the length of the sequence. This is because splice (now) needs to iterate over the sequence to count the number of elements in it. (Because the list needs to record its size.) Simply counting and re-linking the list is still faster than any alternative, and splicing an entire list or a single element are special cases with constant complexity. But, if you have long sequences to splice, you might have to dig around for a better, old-fashioned, non-compliant container.

在向量和列表的情况下，对我来说，主要的区别如下:

向量

A vector stores its elements in contiguous memory. Therefore, random access is possible inside a vector which means that accessing an element of a vector is very fast because we can simply multiply the base address with the item index to access that element. In fact, it takes only O(1) or constant time for this purpose. Since a vector basically wraps an array, every time you insert an element into the vector (dynamic array), it has to resize itself by finding a new contiguous block of memory to accommodate the new elements which is time-costly. It does not consume extra memory to store any pointers to other elements within it.

list

A list stores its elements in non-contiguous memory. Therefore, random access is not possible inside a list which means that to access its elements we have to use the pointers and traverse the list which is slower relative to vector. This takes O(n) or linear time which is slower than O(1). Since a list uses non-contiguous memory, the time taken to insert an element inside a list is a lot more efficient than in the case of its vector counterpart because reallocation of memory is avoided. It consumes extra memory to store pointers to the element before and after a particular element.

因此，记住这些区别，我们通常会考虑内存、频繁的随机访问和插入来决定给定场景中向量和列表的胜者。

如果你不需要经常插入元素，那么向量会更有效。它具有比列表更好的CPU缓存位置。换句话说，访问一个元素使得下一个元素很有可能存在于缓存中，并且可以在不读取慢速RAM的情况下被检索。

我班上的学生似乎无法向我解释什么时候使用向量更有效，但他们在建议我使用列表时看起来很高兴。

这是我的理解

列表: 每一项都包含下一个或上一个元素的地址，所以有了这个功能，你可以随机项，即使它们没有排序，顺序也不会改变:如果你的内存是碎片化的，它是有效的。 但是它还有一个非常大的优势:你可以很容易地插入/删除项，因为你唯一需要做的就是改变一些指针。 缺点: 要读一个随机的条目，你必须从一个条目跳到另一个条目，直到你找到正确的地址。

Vectors: When using vectors, the memory is much more organized like regular arrays: each n-th items is stored just after (n-1)th item and before (n+1)th item. Why is it better than list ? Because it allow fast random access. Here is how: if you know the size of an item in a vector, and if they are contiguous in memory, you can easily predict where the n-th item is; you don't have to browse all the item of a list to read the one you want, with vector, you directly read it, with a list you can't. On the other hand, modify the vector array or change a value is much more slow.

列表更适合用于跟踪可以在内存中添加/删除的对象。 当您希望从大量单个项中访问一个元素时，向量更适合。

我不知道列表是如何优化的，但你必须知道，如果你想要快速读取访问，你应该使用向量，因为STL固定列表有多好，它在读取访问方面不会像向量那样快。

保留迭代器的有效性是使用列表的原因之一。另一种情况是当你不希望在推送物品时重新分配向量。这可以通过巧妙地使用reserve()来管理，但在某些情况下，仅使用列表可能更容易或更可行。