完成堆栈抽象数据类型的顺序、链式表示与实现。实现功能：数值转换，计算器（表达式求值），迷宫求解，判断某个字符串是否是回文

-Completion of the stack abstract data type of the order, said that with the realization of the chain. The realization of functions: numerical conversion calculator (expression evaluation), to solve the maze to determine whether a string is a palindrome