#include<stdio.h>

#include<string.h>

#include<ctype.h>

#define M 1000

struct 

key

{

    

char 

g[20];

};

typedef 

struct 

key KEY;

int 

main()

{

    

KEY k[6];

    

int 

i=0,j=0;

    

char 

a[M],b[M];

    

strcpy(k[0].g,

"begin"

);

    

strcpy(k[1].g,

"if"

);

    

strcpy(k[2].g,

"then"

);

    

strcpy(k[3].g,

"while"

);

    

strcpy(k[4].g,

"do"

);

    

strcpy(k[5].g,

"end"

);

 

    

printf(

"请输入源程序:\n"

);

    

gets(a);

    

while

(a[i]!=

'\0'

)

    

{

        

j=0;

        

if

((isalpha(a[i]))||(a[i]==

'_'

))

        

{

            

while

((a[i]!=

' '

)&&(a[i]!=

'\0'

))

            

{

                

if

((isalpha(a[i]))||(isdigit(a[i])))

                

{

                 

b[j]=a[i];

                 

j++;

                 

i++;

                

}

                

else

                    

break

;

            

}

            

if

((a[i]==

' '

)||(a[i]==

'\0'

))

            

{

                

b[j]=

'\0'

;

                

if

(strcmp(b,k[0].g)==0)

                    

printf(

"begin\t种别码   1\n"

);

                

else 

if

(strcmp(b,k[1].g)==0)

                    

printf(

"if   \t种别码   2\n"

);

                

else 

if

(strcmp(b,k[2].g)==0)

                    

printf(

"then \t种别码   3\n"

);

                

else 

if

(strcmp(b,k[3].g)==0)

                    

printf(

"while\t种别码   4\n"

);

                

else 

if

(strcmp(b,k[4].g)==0)

                    

printf(

"do   \t种别码   5\n"

);

                

else 

if

(strcmp(b,k[5].g)==0)

                    

printf(

"end  \t种别码   6\n"

);

                

else

                    

printf(

"%s  \t种别码   10\n"

,b);

            

}

            

else

            

{

                

b[j]=

'\0'

;

                

printf(

"%s   \t种别码       10\n"

,b);

                

i--;

            

}

        

}

 

        

else 

if

(isdigit(a[i]))

        

{

            

j=0;

            

while

(isdigit(a[i]))

            

{

                 

b[j]=a[i];

                 

j++;

                 

i++;

            

}

            

b[j]=

'\0'

;

            

printf(

"%s    \t种别码    11\n"

,b);

            

i--;

        

}

        

else

        

{

            

switch

(a[i])

            

{

            

case 

'+'

:

                

printf(

"%c   \t种别码   13\n"

,a[i]);

break

;

            

case 

'-'

:

                

printf(

"%c   \t种别码   14\n"

,a[i]);

break

;

            

case 

'*'

:

                

printf(

"%c   \t种别码   15\n"

,a[i]);

break

;

            

case 

'/'

:

                

printf(

"%c   \t种别码   16\n"

,a[i]);

break

;

            

case 

':'

:

                

if

(a[i+1]==

'='

)

                

{   printf(

":=   \t种别码   18\n"

);i++;

break

;}

                

else

                

{   printf(

"%c   \t种别码   17\n"

,a[i]);

break

;}

            

case 

'<'

:

                

if

(a[i+1]==

'='

)

                

{   printf(

"<=   \t种别码   21\n"

);i++;

break

;}

                

if

(a[i+1]==

'>'

)

                

{   printf(

"<>   \t种别码   22\n"

);i++;

break

;}

                

else

                    

printf(

"%c   \t种别码   20\n"

,a[i]);

break

;

            

case 

'>'

:

                

if

(a[i+1]==

'='

)

                

{   printf(

">=   \t种别码   24\n"

);i++;

break

;}

                

else

                    

printf(

"%c   \t种别码   23\n"

,a[i]);

break

;

            

case 

'='

:

                

printf(

"=    \t种别码    25\n"

);

break

;

            

case 

';'

:

                

printf(

";   \t种别码    26\n"

);

break

;

            

case 

'('

:

                

printf(

"(   \t种别码   27\n"

);

break

;

            

case 

')'

:

                

printf(

")   \t种别码   28\n"

);

break

;

            

case 

'#'

:

                

printf(

"#   \t种别码   0\n"

);

break

;

            

default

:

                

printf(

"%c   \t语法错误!\n"

,a[i]);

break

;

            

}

        

}

 

        

i++;

    

}

}