c语言实现算符优先语法分析(共5页)

1、精选优质文档-倾情为你奉上#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zhongjianint 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

2、符优先关系表，大于为1，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(zhongjia

3、ni+ != '#');printf("t");i-=2;return i;char ding()/获取栈顶元素，无视Echar 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; cas

4、e '*':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while (zh!='#'|ch!='#')putz

5、han();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');

6、/归约到E printf("归约n");shuc+=' 'shuc+='>'shuc+='-'shuc+=' 'elsesyn=-1;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"); do ch=getchar(); progi+=ch; while(ch!='#');void scaner()syn=1; ch=progp+; while(

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

8、ngjianq+=')'break;case'i':zhongjianq+='i'break; case'#':zhongjianq+='#'syn=0;break; default: syn=-1;break; void saomiao()p=0;q=0; do 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(&qu