first and follow in compiler design examples| FIRST and FOLLOW| How to find out first and follow ? from a given Grammar

Consider the  following Grammar :

    E  -> TE'
    E' -> +TE'/∈
    T  -> FT'
    T' -> *FT'/∈ 
    F  -> (E)/id

To find the FIRST(E) follow the steps given below:

 STEP1:  Take the production  E-> TE', here the first symbol is T a Non-Terminal then Find the Production of T,

STEP 2: T -> FT', here also a non- terminal occurs at the first position. then find the production of F.

STEP 3:  F -> (E) and F-> id,  here we can see two terminals, we conclude that :
       
 FIRST(E) = { (,id }

Similarly 

FIRST(E')={+,∈}
FIRST(T)={(,id}
FIRST(T')={*,∈}
FIRST(F)={(,id}

IMPLEMENTATION OF FIRST OF A GRAMMAR USING C

Check the sample output..Non terminal must be capital letter, epsilon is represented by # symbol

#include<stdio.h>
#include<ctype.h>

void firstof(char[], char);
void arrangearray(char[], char);
int visited(char );

int noproduction;
char production[100][100];

char visit[100];
int nTerm;
int main()
{
      char option;
      char ch;
      char array[100];
      int c,k;
      printf("\nEnter Total Number of Productions:");
      scanf("%d", &noproduction);
      for(c = 0; c < noproduction; c++)
      {
     printf("\nEnter Production%d:", c + 1);
     scanf("%s", production[c]);
      }
      k=0;
      while(k<noproduction)
      {

     ch=production[k][0];
     if(!visited(ch))
     {
  firstof(array, ch);
  printf("\nFirst(%c):\t{ ", ch);
  for(c = 0; array[c] != '\0'; c++)
  {
     printf("%c,", array[c]);
  }
  printf("}\n");
     }
     k++;

      }
      return 0;
}

void firstof(char* array, char ch)
{
      int c, j, k;
      char tmpresult[100];
      int x;
      tmpresult[0] = '\0';
      array[0] = '\0';
      if(!(isupper(ch)))
      {
     arrangearray(array, ch);
     return ;
      }
      c=0;
      while( c < noproduction)
      {
     if(production[c][0] == ch)
     {
    if(production[c][2] == '#')
    {
   arrangearray(array, '#');
    }
    else
    {
   j = 2;
   while(production[c][j] != '\0')
   {
         x = 0;
         firstof(tmpresult, production[c][j]);
         for(k = 0; tmpresult[k] != '\0'; k++)
         {
        arrangearray(array,tmpresult[k]);
         }
         for(k = 0; tmpresult[k] != '\0'; k++)
         {
        if(tmpresult[k] == '#')
        {
       x = 1;Check the sample output..Non terminal must be capital letter, epsilon is represented by # symbol
#include<stdio.h>
#include<ctype.h>

void firstof(char[], char);
void arrangearray(char[], char);
int visited(char );

int noproduction;
char production[100][100];

char visit[100];
int nTerm;
int main()
{
      char option;
      char ch;
      char array[100];
      int c,k;
      printf("\nEnter Total Number of Productions:");
      scanf("%d", &noproduction);
      for(c = 0; c < noproduction; c++)
      {
     printf("\nEnter Production%d:", c + 1);
     scanf("%s", production[c]);
      }
      k=0;
      while(k<noproduction)
      {

     ch=production[k][0];
     if(!visited(ch))
     {
  firstof(array, ch);
  printf("\nFirst(%c):\t{ ", ch);
  for(c = 0; array[c] != '\0'; c++)
  {
     printf("%c,", array[c]);
  }
  printf("}\n");
     }
     k++;

      }
      return 0;
}

void firstof(char* array, char ch)
{
      int c, j, k;
      char tmpresult[100];
      int x;
      tmpresult[0] = '\0';
      array[0] = '\0';
      if(!(isupper(ch)))
      {
     arrangearray(array, ch);
     return ;
      }
      c=0;
      while( c < noproduction)
      {
     if(production[c][0] == ch)
     {
    if(production[c][2] == '#')
    {
   arrangearray(array, '#');
    }Check the sample output..Non terminal must be capital letter, epsilon is represented by # symbol
#include<stdio.h>
#include<ctype.h>

void firstof(char[], char);
void arrangearray(char[], char);
int visited(char );

int noproduction;
char production[100][100];

char visit[100];
int nTerm;
int main()
{
      char option;
      char ch;
      char array[100];
      int c,k;
      printf("\nEnter Total Number of Productions:");
      scanf("%d", &noproduction);
      for(c = 0; c < noproduction; c++)
      {
     printf("\nEnter Production%d:", c + 1);
     scanf("%s", production[c]);
      }
      k=0;
      while(k<noproduction)
      {

     ch=production[k][0];
     if(!visited(ch))
     {
  firstof(array, ch);
  printf("\nFirst(%c):\t{ ", ch);
  for(c = 0; array[c] != '\0'; c++)
  {
     printf("%c,", array[c]);
  }
  printf("}\n");
     }
     k++;

      }
      return 0;
}

void firstof(char* array, char ch)
{
      int c, j, k;
      char tmpresult[100];
      int x;
      tmpresult[0] = '\0';
      array[0] = '\0';
      if(!(isupper(ch)))
      {
     arrangearray(array, ch);
     return ;
      }
      c=0;
      while( c < noproduction)
      {
     if(production[c][0] == ch)
     {
    if(production[c][2] == '#')
    {
   arrangearray(array, '#');
    }
    else
    {
   j = 2;
   while(production[c][j] != '\0')
   {
         x = 0;
         firstof(tmpresult, production[c][j]);
         for(k = 0; tmpresult[k] != '\0'; k++)
         {
        arrangearray(array,tmpresult[k]);
         }
         for(k = 0; tmpresult[k] != '\0'; k++)
         {
        if(tmpresult[k] == '#')
        {
       x = 1;
       break;
        }
         }
         if(x==0)
         {
        break;
         }
         j++;
   }
    }
     }
 c++;
      }
      return;
}

void arrangearray(char array[], char value)
{
      int tmp;
      for(tmp = 0; array[tmp] != '\0'; tmp++)
      {
     if(array[tmp] == value)
     {
    return;
     }
      }
      array[tmp] = value;
      array[tmp + 1] = '\0';
}

int visited(char ch)
{
 int i=0;
 for(i=0;i<nTerm;i++)
 {
  if(visit[i]==ch)
  {
   return 1;
  }
 }
 visit[i]=ch;
 nTerm++;
 return 0;
}
    else
    {
   j = 2;
   while(production[c][j] != '\0')
   {
         x = 0;
         firstof(tmpresult, production[c][j]);
         for(k = 0; tmpresult[k] != '\0'; k++)
         {
        arrangearray(array,tmpresult[k]);
         }
         for(k = 0; tmpresult[k] != '\0'; k++)
         {
        if(tmpresult[k] == '#')
        {
       x = 1;
       break;
        }
         }
         if(x==0)
         {
        break;
         }
         j++;
   }
    }
     }
 c++;
      }
      return;
}

void arrangearray(char array[], char value)
{
      int tmp;
      for(tmp = 0; array[tmp] != '\0'; tmp++)
      {
     if(array[tmp] == value)
     {
    return;
     }
      }
      array[tmp] = value;
      array[tmp + 1] = '\0';
}

int visited(char ch)
{
 int i=0;
 for(i=0;i<nTerm;i++)
 {
  if(visit[i]==ch)
  {
   return 1;
  }
 }
 visit[i]=ch;
 nTerm++;
 return 0;
}
       break;
        }
         }
         if(x==0)
         {
        break;
         }
         j++;
   }
    }
     }
 c++;
      }
      return;
}

void arrangearray(char array[], char value)
{
      int tmp;
      for(tmp = 0; array[tmp] != '\0'; tmp++)
      {
     if(array[tmp] == value)
     {
    return;
     }
      }
      array[tmp] = value;
      array[tmp + 1] = '\0';
}

int visited(char ch)
{
 int i=0;
 for(i=0;i<nTerm;i++)
 {
  if(visit[i]==ch)
  {
   return 1;
  }
 }
 visit[i]=ch;
 nTerm++;
 return 0;
}

Assembly program to read two decimal numbers, then add them together and finally print out the result (in decimal ) | MASM program to add two 8-bit numbers (decimal)

assume ds:data,cs:code
data segment
num1 db ?
num2 db ?
result db ?
msg1 db 10,13,"enter first number to add : $"
msg2 db 10,13,"enter second number to add : $"
msg3 db 10,13,"result of addition is : $"
data ends
code segment
start:
mov ax,data
mov ds,ax
mov dx,offset msg1
mov ah,9h
int 21h
mov ah,1
int 21h
sub al,30h
mov num1,al
mov dx,offset msg2
mov ah,9h
int 21h
mov ah,1h
int 21h
sub al,30h
mov num2,al
add al,num1
mov result,al
mov ah,0h
aaa
add ah,30h
add al,30h
mov bx,ax
mov dx,offset msg3
mov ah,9
int 21h
mov ah,2
mov dl,bh
int 21h
mov ah,2
mov dl,bl
int 21h
mov ah,4ch
int 21h
code ends
end start