两种用途非常广泛的特殊“vector”:队列、栈 0 out in out back front Queue Stack The point in these special cases is that it is worthwhile,at least for reasons of algorithmic clarity,to think of queues and stacks as being in themselves data structures,rather than being merely special kinds of lists.We can then use specially devised elementary instructions such as “add X to queue A,”or“push X on stack S,”rather than obscure formulations that explicitly involve indices.两种用途非常广泛的特殊“vector”：队列、栈