此代码实现了算符优先文法分析器，实现对整数加减乘除运算表达式的分析和处理。

1．扫描程序，将任何一种整数运算表达式（无变量，操作数为正整数，允许加减乘除四种运算，允许使用括号和多层括号）识别为单词，并能发现单词的拼写错误

2．自底向上分析程序，在栈上实现对单词token串的自底向上分析

3．　　根据算符优先文法的分析步骤，展示分析栈、token串的状态变化、相关量的优先级比较(算符优先分析表)结果输出 、判断当前是否进行规约或移进操作、（若须规约）显示当前应规约的串

4．展示语法树-This code implements the operator precedence grammar analyzer, analysis and processing to achieve subtraction multiplication and division of integers expression. 1. Scanning procedures, will any kind of integer arithmetic expression (no variable operand is a positive integer, subtraction, multiplication and division to allow operation, allowing the use of parentheses and multi parentheses) for word recognition and spelling errors can be found in 2. Bottom-up analysis program on the stack to achieve bottom-up analysis of the word token string 3. According to operator precedence grammar analysis step, showing the analysis of the stack, compares the priority token string status changes, an amount of correlation (operator priority table analysis) and outputs the result, it is determined whether the current statute or be moved into operation (if required statute) Displays the current string should Statute 4. Show syntax tree