本结构是以状态间的弧为核心定义的。其中s1和s2为该弧的初态和终态，s为该弧上接收的字母，in和out分别表示在接收字母后进栈和出栈的字母。为了方便查找和不使弧的个数受到限制，本程序将节点以链表的方式存储-This structure is state between the arc as the core defined. One for the arc s2 s1 and the initial state and eventually state, s for the arc on rec