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1、#include#include#include#define_KEY_WORD_END"waitingforyourexpanding"typedefstruct{inttypenum;char*word;}WORD;charinput[255];chartoken[255]="";intp」nput;intp_token;charch;char*KEY_WORDS[]={"begin,,；,if,,/"thenH/,,while"；,do,,/,,
2、end,,/_KEY_WORD_END};WORD*scaner();voidIrParserf);voidyucu();voidstatement));voidstatement();voidexpression();voidterm();voidfactor();intsyn;intkk;WORD*oneword=newWORD;voidmain(){intover=l;printf("EnterYourwords(endwith#):");scanf("%[A#]s",input);p_input=O;
3、printf('"Yourwords:%s蔦input);oneword=scaner();IrParserf);printf("press#toexit:");scanf(,,%[A#]s"/input);}voidIrParserf)讦(syn==l){oneword=scaner();yucu()；讦(syn==6){oneword=scaner();if(syn==O&&kk==O){printff吆s”,“success”)；}else{if(kk!=l){printf(,,%s,,/n
4、缺'end'错误”);kk=l;}}}}else{printf(”％s“,“缺'begin'错误”);kk=l;}}voidyucu(){statement!);while(syn==26){oneword=scaner();statement));}}voidstatement(){if(syn==10){oneword=scaner();if(syn==18){oneword=scaner();expression();}else{printf(”％sT赋值号错误”);kk=l;}}else{printf
5、("%s'7'语句错误”);kk=l;}voidexpression(){term();while(syn==13
6、
7、syn==14){oneword=scaner();term();}}voidterm(){factor();while(syn二=15
8、
9、syn二=16){oneword=scaner();factor();}}voidfactor(){if(syn==10
10、
11、syn==ll){oneword=scaner();}elseif(syn==27){oneword=scaner();expres
12、sion();if(syn==28){oneword=scaner();}else{printf(”％s罗丁错误”);kk=l;}}else{printf(”％s：表达式错误“);kk=l;}}charm_getch(){ch=input[p_input];p_input=p_input+1;return(ch);}voidgetbc(){while(ch=='J
13、ch==10){ch=input[p_input];p_input=p_input+1;}}voidconcat(){token[p_token]
14、=ch;p_token二p_token+1;token[p_token]=' ';}intletter(){if(ch>='a,&&chv-zT
15、ch>=7V&&ch<='Z,)return1;elsereturn0;}intdigit(){if(ch>=,0,&&ch<=,9')return1;elsereturn0;}intreserve(){inti=0;while(strcmp(KEY_WORDS[i]/_KEY_WORD_END)){if(!strcmp(KEY_WORDS[i],token)){
16、returni+1;}i=i+l;}return10;}voidretract(){p」nput=p」nput-1;}char*dtb(){returnNULL;}WORD*seaner(){WORD*myword=newWORD;myword->typenum=10;syn二myword・>typenum;myword->word=,,n;p_token=0;m_getch();getbc();i
