1) 建立栈并进行一些元素入栈，实现链栈的建立及入栈的基本操作； (2)实现某些元素的出栈，实现链栈的出栈的操作；(1) set up the stack and carry out some elements into the stack, to achieve the establishment of the chain stack and the basic operation of the stack; (2) the stack of some elements can be re