Develop functions to find FIRST

#include<stdio.h>

#include<ctype.h>

void FIRST(char[],char );

void result(char[],char);

intnop;

char prod[10][10];

void main()

{

int i;

char choice;

char c;

char res1[20];

clrscr();

printf("How many number of productions ? :");

scanf(" %d",&nop);

printf("enter the production string like E=E+T\n");

for(i=0;i<nop;i++)

{

printf("Enter productions Number %d : ",i+1);

scanf(" %s",prod[i]);

}

do

{

printf("\n Find the FIRST of :");

scanf(" %c",&c);

memset(res1,’0’,sizeof(res));

FIRST(res1,c);

printf("\n FIRST(%c)= { ",c);

for(i=0;res1[i]!='\0';i++)

printf(" %c ",res1[i]);

printf("}\n");

printf("press 'y' to continue : ");

scanf(" %c",&choice);

}

while(choice=='y'||choice =='Y');

}

void FIRST(char res[],char c)

{

inti,j,k;

char subres[5];

int eps;

subres[0]='\0';

res[0]='\0';

memset(res,’0’,sizeof(res));

memset(subres,’0’,sizeof(res));

if(!(isupper(c)))

{

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result(res,c);

return ;

}

for(i=0;i<nop;i++)

{

if(prod[i][0]==c)

{

if(prod[i][2]=='$')

result(res,'$');

else

{

j=2;

while(prod[i][j]!='\0')

{

eps=0;

FIRST(subres,prod[i][j]);

for(k=0;subres[k]!='\0';k++)

result(res,subres[k]);

for(k=0;subres[k]!='\0';k++)

if(subres[k]=='$')

{

eps=1;

break;

}

if(!eps)

break;

j++;

}

}

}

}

return ;

}

void result(char res[],char val)

{

int k;

for(k=0 ;res[k]!='\0';k++)

if(res[k]==val)

return;

res[k]=val;

res[k+1]='\0';

}

OUTPUT:

How many number of productions ?:8

enter the production string like E=E+T

Enter productions Number 1 : E=TX

Enter productions Number 2 : X=+TX

Enter productions Number 3 : X=$

Enter productions Number 4 : T=FY

Enter productions Number 5 : Y=*FY

Enter productions Number 6 : Y=$

Enter productions Number 7 : F=(E)

Enter productions Number 8 : F=i

Find the FIRST of :X

FIRST(X)= { + $ }

press 'y' to continue : Y

Find the FIRST of :F

FIRST(F)= { ( i }

press 'y' to continue : Y

Find the FIRST of :Y

FIRST(Y)= { * $ }

press 'y' to continue : Y

Find the FIRST of :E

FIRST(E)= { ( i }

press 'y' to continue : Y

Find the FIRST of :T

FIRST(T)= { ( i }

press 'y' to continue : N