DFA COMPLETE.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <string.h>
/* Define an array of transitions to sort. */
int transtablecount;
char id[100];
struct transition
  {
    const char curstate[7];
    const char nextstate[5];
  };
struct transition transtable[100];
int transition_cmp (const struct transition *t1, const struct transition *t2)
{
  return strcmp (t1->curstate, t2->curstate);
}

char* find_transition (const char *curstate) {
  struct transition target, *result;
  strcpy(target.curstate, curstate);
  result = bsearch (&target, transtable, transtablecount, sizeof (struct transition),
                    transition_cmp);
  if(result)
  {
      return result->nextstate;
  }
  else
    return "";
/*  if (result)
    printf("Next state: %s\n",result->nextstate);
  else
    printf ("Couldn't find %s.\n", curstate); */
}
int main (void)
{
    char states[10][3];
    char inputsymbols[20],tempcurstate[5],nextstate[5],presentstate[5];
    char curstate[10];
    int i,j,k,numstates,numinps;
    char curchar;
    struct transition temp;
    printf("Enter number of states in DFA: ");
    scanf("%d",&numstates);
    printf("Enter the states of DFA ( 'q0' for initial state and 'qf' for final state:\n");
    for(i=0;i<numstates;i++)
    {
        scanf("%s",states[i]);
    }
    printf("Enter number of input symbols: ");
    scanf("%d",&numinps);
    printf("Number of input symbols: %d\n",numinps);
    for(i=0;i<numinps;i++)
    {
        scanf(" %c",&inputsymbols[i]);
    }
    strcpy(tempcurstate,"");
    transtablecount = 0;
    for(i=0;i<numstates;i++)
    {
        printf("Enter transitions for state %s\n",states[i]);
        for(j=0;j<numinps;j++)
        {
            strcpy(tempcurstate,states[i]);
            for(k=0;k<sizeof(tempcurstate);k++)
            {
                if(tempcurstate[k] == '\0')
                {
                    tempcurstate[k] = inputsymbols[j];
                    tempcurstate[k+1] = '\0';
                    break;
                }
            }
            strcpy(transtable[transtablecount].curstate,tempcurstate);
            printf("\tEnter next state on input %c:",inputsymbols[j]);
            scanf("%s",nextstate);
            strcpy(transtable[transtablecount].nextstate ,nextstate);
            transtablecount++;
        }
    }
    qsort (transtable, transtablecount-1, sizeof (struct transition), transition_cmp);

    for (i = 0; i < transtablecount; i++)
        printf("\nInput: %s Output: %s\n",(&transtable[i])->curstate,(&transtable[i])->nextstate);
    printf ("\n");
    while(1)
    {
    printf("Enter a string to show it's Instantaneous Description: ");
    scanf("%s",&id);
    printf("%s",id);
    strcpy(curstate,"q0");
    for(i=0;i<strlen(id);i++)
    {
        strcpy(presentstate,curstate);
        curchar = id[i];
        if(curchar == '\0')
            break;
        for(j=0;j<sizeof(presentstate);j++)
        {
            if(presentstate[j] == '\0')
            {
                presentstate[j] = curchar;
                presentstate[j+1] = '\0';
                break;
            }
        }
        strcpy(curstate,find_transition(presentstate));
        printf("\nINPUT SYMBOL: %c , NEXT STATE: %s\n",curchar,curstate);
    }
    if(strcmp(curstate,"qf") == 0)
        printf("STRING ACCEPTED");
    else
        printf("STRING NOT ACCEPTED");
    }
    return 0;
}