I would love to have a debugged copy of the finite state machine code below. I tried debugging but could not, all the machine has to do is to spell check the word "and",an equivalent program using case is welcomed.

#include<cstdlib>
#include<stdio.h>
#include<string.h>

#include<iostream>
#include<string>

using namespace std;

char in_str;
int n;
void spell_check()
{
     char data[256];
     int i;
     FILE *in_file;
in_file=fopen("C:\\Users\\mytorinna\\Desktop\\a.txt","r+");
     while (!feof(in_file))
     {   
         for(i=0;i<256;i++)
           {
           fscanf(in_file,"%c",in_str);
           data[i]=in_str;
           }
           //n = strlen(in_str);
           //start(data);
           cout<<data;
     }
}

void start(char data)
{

   // char next_char;

     //int i = 0;
    // for(i=0;i<256;i++)
    // if (n == 0)
     {
        if(data[i]="a")
        {
         state_A(); 
         exit;             
        }
        else
        {
            cout<<"I am comming";
        }
          // cout<<"This is an empty string";
          // exit();//do something here to terminate the program
     }
     }
void state_A(int i)
{
     if(in_str[i] == 'n')
     {
                  i++;
                  if(i<n) state_AN(i);
                  else error();
     }
     else error();
}

void state_AN(int i)
{
     if(in_str[i] == 'd')
     {
                  if(i == n-1)
                       cout<<" Your keyword spelling is correct";
                  else
                      cout<<"Wrong keyword spelling";
     }
}

int main()
{
    spell_check();
    system("pause");
    return 0;
}