WAP to check whether string is accepted or not for entered grammar - Compiler Construction Lab file

WAP to check whether string is accepted or not for entered grammar

#include<iostream.h>
#include<conio.h>
#include<string.h>
#include<stdio.h>
void main()
{
 char string[20];
 int state=0,count=0;
 clrscr();
 cout<<"the grammar is: S->aS, S->Sb, S->ab \n";
 cout<<"enter the string to be checked \n";
 gets(string);
 while(string[count]!='\0')
  {
    switch(state)
    {
    case 0: if (string[count]=='a')
  state=1;
  else
  state=3;
  break;
   case 1: if (string[count]=='a')
  state=1;
  else if(string[count]=='b')
  state=2;
  else
  state=3;
  break;
   case 2: if (string[count]=='b')
  state=2;
  else
  state=3;
  break;
   default: break;
  }
  count++;
  if(state==3)
  break;
 }
 if(state==2)
  cout<<"string is accepted";
  else
  cout<<"string is not accepted";
  getch();
 }

OUTPUT: