摘要：
Given initially empty stacks, there are three types of operations: 1 s v: Push the value onto the top of the -th stack. 2 s: Pop the topmost value out 阅读全文
摘要：
A tree is a well-known data structure that is either empty (null, void, nothing) or is a set of one or more nodes connected by directed edges between 阅读全文
摘要：
The prototypical computer adventure game, first designed by Will Crowther on the PDP-10 in the mid-1970s as an attempt at computer-refereed fantasy ga 阅读全文