Theory Of Computation:Algorithm and Coding for Evaluation of e-NFA .

Algorithm:

Step 1: Get the string.

      for(k=0;k(x[k]=getchar())!='\n'; k⁺⁺)

Step 2: Set count=k and flag=a (starting state).

Step 3: For k=0 to k<count

                                             i.            Check the flag.

                                           ii.            If flag=state(any possible state of automata), choose that state.

                                          iii.            Inside that state

If x[k]=1

flag=state1(i.e another state that is reached when input bit to present  state is 1).

                                    Else

flag=state2 (i.e another state that is  reached when input bit to present state is 0).

                                         iv.            Increment the value of k.

Step 4: If flag=any final state

         Display string is accepted.

             Else

                       Display string is not accepted.

Step 5: End of the program.

Coding:
#include<stdio.h>
#include<conio.h>
void main()
{
 int k,count,a=0,b=1,c=2,d=3,e=4,phai=5,flag;
 char x[15];
 clrscr();
 printf("\n Evaluation of   -NFA");
 printf("\n Enter the string: \n");
 for(k=0;(x[k]=getchar())!='\n';k++);
 count=k;
 flag=a;
 for(k=0;k<count;k++)
 {
  if(flag==a)
  {
   if(x[k]=='1')
   {
    if(x[k+1]=='\n')
     flag=e;
    else
     flag=d;
   }
   else
   {
    if(x[k+1]=='\n')
     flag=e;
    else if(x[k+1]=='0')
    {
     if(x[k+2]=='\n')
      flag=d;
     else
      flag=a;
    }
    else
    {
     if(x[k+2]=='\n')
      flag=b;
     else if(x[k+2]=='1')
     {
      if(x[k+3]=='\n')
       flag=c;
      else
       flag=d;
     }
     else
     {
      if(x[k+3]=='\n')
       flag=d;
      else
       flag=c;
     }
    }
   }
  }
  else if(flag==b)
  {
   if(x[k]=='0')
    flag=c;
   else
    flag=e;
  }
  else if(flag==c)
  {
   if(x[k]=='0')
    flag=phai;
   else
    flag=b;
  }
  else if(flag==d)
  {
   if(x[k]=='0')
    flag=e;
   else
    flag=d;
  }
  else if(flag==e)
  {
   flag=phai;
  }
  else
  {
   flag=phai;
  }
 }
 if(flag==e)
   printf("\n String is accepted.");
 else
   printf("\n String is not accepted.");
 getch();
}