c语言实现算符优先语法分析

1、_#include<stdio.h>char prog100,zhongjian100,shu500;char ch,zh;int syn,p,q,a,b,c,d; /p 指向 prog ， q 指向 zhongjian int table88=1,1,-1,-1,-1,1,-1,1,1,1,-1,-1,-1,1,-1,1,1,1,1,1,-1,1,-1,1,1,1,1,1,-1,1,-1,1,-1,-1,-1,-1,-1,-1,-1,0,1,1,1,1,0,1,0,1,1,1,1,1,0,1,0,1,-1,-1,-1,-1,-1,0,-1,-1;/ 存储算符优先关系表，大于为1，

2、小于或等于为 -1 ，其它为 0 表示出错char zhan100;/数组栈int z,j;/z为栈顶指针 ,j为 zhongjian数组指针void push(char ch)/入栈zhanz+=ch;void pop()/出栈z-;void putzhan()/打印栈内字符for(int i=0;i<z;i+)printf("%c",zhani);printf("t");int putzhong()/打印数组中剩余字符int i=j;doprintf("%c",zhongjiani);while(zhongjiani+ !=

3、 '#');printf("t");i-=2;return i;char ding()/获取栈顶元素，无视E精品资料_char a;q=z-1;doa=zhanq-;while(a='E');return a;char ding2()/获取栈顶元素char a;q=z-1;a=zhanq;return a;int findint(char ch) /*将字符转为数字，以得到算符优先值*/int t;switch(ch)case '+':t=0;break;case '-':t=1;break;case '

4、;*':t=2;break;case '/':t=3;break;case '(':t=4;break;case ')':t=5;break;case 'i':t=6;break;case '#':t=7;return t;void chu()/初始化zhan0='#'z=1;c=0;j=0;syn=0;zh=ding();ch=zhongjianj;void analyse()/分析精品资料_while (zh!='#'|ch!='#')putzhan();

5、d=putzhong();a=findint(zh);b=findint(ch);if (tableab=-1)push(ch);j+;printf("移进 n");else if (tableab=1)for(int m=d;m>=j;m-)shuc+=zhongjianm;for(int i=z-1;i>0;i-)shuc+=zhani;zh=ding2();if(zh='i') /当前比较为i, 出栈一次pop();else/当前比较不为i, 出栈三次pop();pop();pop();push('E');/归约到 Epri

6、ntf("归约 n");shuc+=' 'shuc+='>'shuc+='-'shuc+=' 'elsesyn=-1;精品资料_break;zh=ding();ch=zhongjianj;void loadch()/读入所有字符串int i=0;printf("请输入要进行算符优先分析的字符串:n");doch=getchar();progi+=ch;while(ch!='#');void scaner()syn=1;ch=progp+;while(ch=' &

7、#39;|ch='n')ch=progp+;switch(ch)case'+':zhongjianq+='+'break;case'-':zhongjianq+='-'break;case'*':zhongjianq+='*'break;case'/':zhongjianq+='/'break;case'(':zhongjianq+='('break;case')':zhongjianq+=')&

8、#39;break;case'i':zhongjianq+='i'break;case'#':zhongjianq+='#'syn=0;break;default: syn=-1;break;void saomiao()p=0;q=0;do精品资料_scaner();if(syn=-1)printf("输入符号有误!n");break;while(syn!=0);void main()loadch();saomiao();if(syn=0)chu();analyse();printf("#Et#t结束 n");if (syn=0)printf("该字符串可被文法识别n");printf("E");for(int i=c;i>=0;i-