0916 词法分析第二次作业

#include<stdio.h>

#include <string.h>

#include<iostream.h>

main(){

    char a[200];

    char cf,bf;

    int i,b;

    b=0;

    printf("请输入字符(输入#结束):");

    do

    {

         scanf("%c",&cf);

         a[b++]=cf;

    }while(cf!='#');

    for(i=0;i<b;i++)

    {

        bf=a[i];

        if(bf>='a'&&cf<='z')

        {

            if(a[i]=='b'&&a[i+1]=='e'&&a[i+2]=='g'&&a[i+3]=='i'&&a[i+4]=='n')

            {

                printf("<1,begin > ");

            i=i+4;

            continue;

            }

            else if(a[i]=='i'&&a[i+1]=='f')

            {

                printf("<2,if > ");

            i=i+1;

            continue;

            }

            else if(a[i]=='t'&&a[i+1]=='h'&&a[i+2]=='e'&&a[i+3]=='n')

            {

                printf("<3,then > ");

            i=i+3;

            continue;

            }

            else if(a[i]=='w'&&a[i+1]=='h'&&a[i+2]=='i'&&a[i+3]=='l'&&a[i+4]=='e')

            {

                printf("<4,while > ");

            i=i+4;

            continue;

            }

            else if(a[i]=='d'&&a[i+1]=='o')

            {

                printf("<5,do > ");

            i=i+1;

            continue;

            }

            else if(a[i]=='e'&&a[i+1]=='n'&&a[i+2]=='d')

            {

                printf("<6,end > ");

            i=i+2;

            continue;

            }

            else if(a[i]=='l'&&a[i+1]=='('&&a[i+2]=='l'&&a[i+3]=='|'&&a[i+4]=='d'&&a[i+5]==')'&&a[i+6]=='*')

            {

                printf("<10,l(l|d)* > ");

            i=i+6;

            continue;

            }

            else if(a[i]=='d'&&a[i+1]=='d'&&a[i+2]=='*')

            {

                printf("<11,dd* > ");

            i=i+2;

            continue;

            }

        }

        if(bf==':')

            if(a[i+1]=='='){

                printf("<18,:= > ");

                i=i+1;

                continue;}

         if(bf=='<')

            if(a[i+1]=='='){

                printf("<21,<= > ");

                i=i+1;

                continue;}

         if(bf=='<')

            if(a[i+1]=='>'){

                printf("<22,<> > ");

                i=i+1;

                continue;}

         if(bf=='>')

            if(a[i+1]=='='){

                printf("<24,>= > ");

                i=i+1;

                continue;}

        switch(bf)

        {

        case '+':

            printf("<13,%c > ",bf);

            break;

         case '-':

            printf("<14,%c > ",bf);

            break;

         case '*':

            printf("<15,%c > ",bf);

            break;

         case '/':

            printf("<16,%c > ",bf);

            break;

         case ':':

            printf("<17,%c > ",bf);

            break;

         case '(':

            printf("<27,%c > ",bf);

            break;

         case ')':

            printf("<28,%c > ",bf);

            break;

         case '#':

            printf("<0,%c > ",bf);

            break;

         case '>':

            printf("<23,%c > ",bf);

            break;

         case '<':

            printf("<20,%c > ",bf);

            break;

         case ';':

            printf("<26,%c > ",bf);

            break;

        }

    }

}

原文地址:https://www.cnblogs.com/huang123/p/4825881.html