設(shè)計(jì)一個(gè)給定文法和對(duì)應(yīng)的FIRSTVT和LASTVT集

1、實(shí)驗(yàn)二 算符優(yōu)先分析器#include "stdio.h"#include "stdlib.h"#include "iostream.h"char data2020;/算符優(yōu)先關(guān)系char s100;/模擬符號(hào)棧 schar lable20;/文法終極符集char input100;/文法輸入符號(hào)串char string2010;/用于輸入串的分析int k;char a;int j;char q;int r; /文法規(guī)則個(gè)數(shù)int r1; /轉(zhuǎn)化后文法規(guī)則個(gè)數(shù)char st1030;/用來(lái)存儲(chǔ)文法規(guī)則char first1010;/

2、文法非終結(jié)符 FIRSTVT 集char last1010;/文法非終結(jié)符 LASTVT集int fflag10=0;/標(biāo)志第 i 個(gè)非終結(jié)符的 FIRSTVT集是否已求出int lflag10=0;/標(biāo)志第 i 個(gè)非終結(jié)符的 LASTVT集是否已求出int deal(); /對(duì)輸入串的分析int zhongjie(char c);/判斷字符 c 是否是終極符int xiabiao(char c);/求字符 c 在算符優(yōu)先關(guān)系表中的下標(biāo)void out(int j,int k,char *s);/打印 s 棧void firstvt(char c);/求非終結(jié)符 c 的 FIRSTVT集voi

3、d lastvt(char c);/求非終結(jié)符 c 的 LASTVT集void table();/創(chuàng)建文法優(yōu)先關(guān)系表void main() int i,j,k=0;printf(" 請(qǐng)輸入文法規(guī)則數(shù)： "); scanf("%d",&r);printf(" 請(qǐng)輸入文法規(guī)則： n");for(i=0;i<r;i+)scanf("%s",sti); / 存儲(chǔ)文法規(guī)則，初始化 FIRSTVT 集和 LASTVT集*/firsti0=0; /*firsti0和 lasti0 分別表示 sti0 非終極 符的

4、FIRSTVT集和 LASTVT集中元素的個(gè)數(shù) */lasti0=0;判斷文法是否合法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("

5、 不是算符文法 !n");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();FIRSTVT集LASTVT集printf(" 每個(gè)非終結(jié)符的 FIR

6、STVT 集為： n"); / 輸出每個(gè)非終結(jié)符的 for(i=0;i<r;i+)printf("%c: ",sti0);for(j=0;j<firsti0;j+)printf("%c ",firstij+1);printf("n");printf(" 每個(gè)非終結(jié)符的 LASTVT集為： n"); / 輸出每個(gè)非終結(jié)符的 for(i=0;i<r;i+)printf("%c: ",sti0);for(j=0;j<lasti0;j+)printf("%c

7、",lastij+1); printf("n");printf(" 算符優(yōu)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");#結(jié)束 :");pri

8、ntf(" 請(qǐng)輸入文法輸入符號(hào)串以 scanf("%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+='

9、-' textxy+='>'elsetextxy=stij;y+;textxy='0'x+;y=0;r1=x;輸出轉(zhuǎn)化后的文法規(guī)則串求每個(gè)終結(jié)符的推導(dǎo)結(jié)果 （去掉 "->" 后的轉(zhuǎn)化文法，用于最后的規(guī)約 ）*/printf(" 轉(zhuǎn)化后的文法為 :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+)

10、 stringil=textij;stringil='0'for(i=0;i<x;i+) for(j=1;textij+1!='0'j+) if(zhongjie(textij)&&zhongjie(textij+1)m=xiabiao(textij);n=xiabiao(textij+1); datamn='='if(textij+2!='0'&&zhongjie(textij)&&zhongjie(textij+2)&&!zhong jie(textij+1

11、)m=xiabiao(textij);n=xiabiao(textij+2); datamn='=' if(zhongjie(textij)&&!zhongjie(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

12、(stk0=textij)break;n=xiabiao(textij+1);for(t=0;t<lastk0;t+)m=xiabiao(lastkt+1);datamn='>'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

13、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+1; m=0; do if(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;c-do=_=s匸 gkum

14、hs匸 Mo一>!.E=_=SO=IIM 宀+LU+U文=邁匸"旦二3匸(UE七宀(-L-HS1S斤當(dāng)巨3&一(+iuv5>L)04ru 一(+xo=ms！4v>lo艾)04*1A-LS<1 怪(E=_=SO:65UOIIZM(r"L+旦gs=o云"L+巨gSMopoulu=+o=_=se_HUOH"二 6舉宀三 eaiq(osogSM(+±v_o.!l)04 cwr 二£-_ (0elp)2se- po>匸"二詈lastin=stim;n+;elseif(zhongjie(stim-1

15、)lastin=stim-1;n+;if(stim!=c)lastvt(stim);for(j=0;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;輸入串的長(zhǎng)度棧置初值 計(jì)算輸入串的長(zhǎng)度int x,y;int z; /

16、k=1;sk='#' / for(i=0;inputi!='0'i+); / z=i-;i=0;while(a=inputi)!='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(" 規(guī)約 n"); do q=sj; if(zhongjie(sj-1) j=j-1; else j=

17、j-2; x=xiabiao(sj); y=xiabiao(q);while(dataxy!='<');int m,n,N;for(m=j+1;m<=k;m+) 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; else if(zhon

18、gjie(sm) if(sm=stringNn) sj+1=stringN0; break;k=j+1;if(k=2&&a='#')out(1,k,s); printf("%c",a); out(i+1,z,input); printf(" 結(jié)束 n");輸入串符合文法的定義printf(" 輸入串符合文法的定義！ n"); return 1; /else移進(jìn)if(dataxy='<'|dataxy='=') / out(1,k,s); printf("%c",a); out(i+1,z,input); printf(" 移進(jìn) 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;