实验二编译原理语法分析算符优先

1、实验二 语法分析算符优先分析程序一实验要求 选择最有代表性的语法分析方法算符优先法； 选择对各种常见程序语言都用的语法结构，如赋值语句（尤指表达式）作为分析对象，并且与所选语法分析方法要比较贴切。 实习时间为6学时。二实验内容及要求（1）根据给定文法，先求出FirstVt和LastVt集合，构造算符优先关系表（要求算符优先关系表 输出到屏幕或者输出到文件）；（2）根据算法和优先关系表分析给定表达式是否是该文法识别的正确的算术表达式（要求输出归约过程）（3）给定表达式文法为： G(E): E#E#EE+T | TTT*F |FF(E)|i(4)分析的句子为: (i+i)*i和i+i)*i三.实验

2、代码#include "stdafx.h"#include "stdio.h"#include "stdlib.h"#include "iostream.h"int k; char a; int j; char q; int r; int r1; char st1030; char data2020; char s100; char lable20; char input100; char string2010; char first1010; char last1010; int fflag10=0; int l

3、flag10=0; int deal(); int zhongjie(char c); int xiabiao(char c); void out(int j,int k,char *s); void firstvt(char c); void lastvt(char c); void table(); void main()int i,j,k=0; printf("请输入文法规则数：");scanf("%d",&r);printf("请输入文法规则：n");for(i=0;i<r;i+)scanf("%s&q

4、uot;,sti); firsti0=0; lasti0=0;for(i=0;i<r;i+) for(j=0;stij!='0'j+)if(sti0<'A'|sti0>'Z')printf("不是算符文法!n"); exit(-1);if(stij>='A'&&stij<='Z') if(stij+1>='A'&&stij+1<='Z')printf("不是算符文法!n"

5、); exit(-1); for(i=0;i<r;i+)for(j=0;stij!='0'j+)if(stij<'A'|stij>'Z')&&stij!='-'&&stij!='>'&&stij!='|')lablek+=stij;lablek='#'lablek+1='0' table(); /输出每个非终结符的FIRSTVT集printf("每个非终结符的FIRSTVT集为：n&qu

6、ot;); for(i=0;i<r;i+)printf("%c: ",sti0);for(j=0;j<firsti0;j+)printf("%c ",firstij+1);printf("n");/输出每个非终结符的LASTVT集printf("每个非终结符的LASTVT集为：n"); for(i=0;i<r;i+)printf("%c: ",sti0);for(j=0;j<lasti0;j+)printf("%c ",lastij+1);printf

7、("n");printf("算符优先分析表如下:n");for(i=0;lablei!='0'i+) printf("t%c",lablei);printf("n"); for(i=0;i<k+1;i+)printf("%ct",lablei);for(j=0;j<k+1;j+)printf("%ct",dataij);printf("n");printf("请输入文法输入符号串以#结束:");scanf(&

8、quot;%s",input); deal();void table()char text2010;int i,j,k,t,l,x=0,y=0;int m,n;x=0;for(i=0;i<r;i+)firstvt(sti0);lastvt(sti0);for(i=0;i<r;i+)textxy=sti0;y+;for(j=1;stij!='0'j+)if(stij='|')textxy='0'x+;y=0;textxy=sti0;y+;textxy+='-'textxy+='>'else

9、textxy=stij;y+;textxy='0'x+;y=0;r1=x; /输出转化后的文法规则串printf("转化后的文法为:n");for(i=0;i<x;i+) printf("%sn",texti);for(i=0;i<x;i+) stringi0=texti0;for(j=3,l=1;textij!='0'j+,l+)stringil=textij;stringil='0'for(i=0;i<x;i+)for(j=1;textij+1!='0'j+)if(zh

10、ongjie(textij)&&zhongjie(textij+1)m=xiabiao(textij);n=xiabiao(textij+1);datamn='='if(textij+2!='0'&&zhongjie(textij)&&zhongjie(textij+2)&&!zhongjie(textij+1)m=xiabiao(textij);n=xiabiao(textij+2);datamn='='if(zhongjie(textij)&&!zhongjie(

11、textij+1)for(k=0;k<r;k+)if(stk0=textij+1)break;m=xiabiao(textij);for(t=0;t<firstk0;t+)n=xiabiao(firstkt+1);datamn='<'if(!zhongjie(textij)&&zhongjie(textij+1)for(k=0;k<r;k+)if(stk0=textij)break;n=xiabiao(textij+1);for(t=0;t<lastk0;t+)m=xiabiao(lastkt+1);datamn='>

12、'm=xiabiao('#');for(t=0;t<first00;t+)n=xiabiao(first0t+1);datamn='<'n=xiabiao('#');for(t=0;t<last00;t+)m=xiabiao(last0t+1);datamn='>'datann='=' /求FIRSTVT集void firstvt(char c) int i,j,k,m,n;for(i=0;i<r;i+)if(sti0=c)break;if(fflagi=0)n=firsti0

13、+1;m=0;doif(m=2|stim='|')if(zhongjie(stim+1)firstin=stim+1;n+;elseif(zhongjie(stim+2)firstin=stim+2;n+;if(stim+1!=c)firstvt(stim+1);for(j=0;j<r;j+)if(stj0=stim+1)break;for(k=0;k<firstj0;k+)int t;for(t=0;t<n;t+)if(firstit=firstjk+1)break;if(t=n)firstin=firstjk+1;n+;m+;while(stim!=

14、9;0');firstin='0'firsti0=-n;fflagi=1; /求LASTVT集void lastvt(char c) int i,j,k,m,n;for(i=0;i<r;i+)if(sti0=c)break;if(lflagi=0)n=lasti0+1;m=0;doif(stim+1='0'|stim+1='|')if(zhongjie(stim)lastin=stim;n+;elseif(zhongjie(stim-1)lastin=stim-1;n+;if(stim!=c)lastvt(stim);for(j=0

15、;j<r;j+)if(stj0=stim)break;for(k=0;k<lastj0;k+)int t;for(t=0;t<n;t+)if(lastit=lastjk+1)break;if(t=n)lastin=lastjk+1;n+;m+;while(stim!='0');lastin='0'lasti0=-n;lflagi=1;int deal()int i,j;int x,y;int z; k=1;sk='#' for(i=0;inputi!='0'i+); z=i-;i=0;while(a=inputi

16、)!='0')if(zhongjie(sk)j=k;elsej=k-1;x=xiabiao(sj);y=xiabiao(a);if(dataxy='>')out(1,k,s);printf("%c",a);out(i+1,z,input);printf("规约n");doq=sj;if(zhongjie(sj-1)j=j-1;else j=j-2;x=xiabiao(sj);y=xiabiao(q);while(dataxy!='<');int m,n,N;for(m=j+1;m<=k;m

17、+)for(N=0;N<r1;N+)for(n=1;stringNn!='0'n+)if(!zhongjie(sm)&&!zhongjie(stringNn)if(zhongjie(sm+1)&&zhongjie(stringNn+1)&&sm+1=stringNn+1)sj+1=stringN0; break; elseif(zhongjie(sm)if(sm=stringNn)sj+1=stringN0; break; k=j+1;if(k=2&&a='#')out(1,k,s);prin

18、tf("%c",a);out(i+1,z,input);printf("结束n");printf("输入串符合文法的定义！n");return 1; elseif(dataxy='<'|dataxy='=') out(1,k,s);printf("%c",a);out(i+1,z,input);printf("移进n");k+;sk=a;i+;elseprintf("nflase");return 0;printf("nflase");return 0;void out(int j,int k,char *s)int n=0;int i;for(i=j;i<=k;i+)printf("%c",si);n+;for(;n<15;n+)printf(" ");/判断字符c是否是终极符int zhongjie(char c) int i;for(i=0;l