dfa.c

#include<stdio.h>
#include<malloc.h>
#include<string.h>
#define MAX_INPUTS 10
#define MAX_INPUT_SIZE 5
#define MAX_STATES 20
#define MAX_STATE_SIZE 5
#define MAX_ID_SIZE 100
int get_id(char str[], char str_arr[][MAX_STATE_SIZE], int len)
{
	int i;
	for (i = 0; i<len; i++)
	{
		if (strcmp(str, str_arr[i]) == 0)
			return i;
	}
	return -1;
}
int main()
{
	char inputs[MAX_INPUTS][MAX_INPUT_SIZE],initial_states[MAX_STATE_SIZE],final_states[MAX_STATES][MAX_STATE_SIZE],initial_state[MAX_STATE_SIZE];
	char states[MAX_STATES][MAX_STATE_SIZE];
	char*** transitions;
	char temp_state[MAX_STATE_SIZE], temp_input[MAX_INPUT_SIZE], id_string[MAX_ID_SIZE], cur_inp[MAX_INPUT_SIZE], cur_state[MAX_STATE_SIZE];
	int i, j, k, numinps, numstates, row_id, col_id,num_final_states;
	printf("Enter number of input states: ");
	scanf("%d", &numstates);
	printf("Enter number of input symbols: ");
	scanf("%d", &numinps);
	transitions = (char ***)malloc(sizeof(char**)*numstates);
	printf("Enter the input states: \n");
	for (i = 0; i<numstates; i++)
	{
		scanf(" %s", temp_state);
		strcpy(states[i], temp_state);
	}
	printf("Enter the input symbols: \n");
	for (i = 0; i<numinps; i++)
	{
		scanf(" %s", temp_input);
		strcpy(inputs[i], temp_input);
	}
	printf("Enter the transitions:\n");
	for (i = 0; i<numstates; i++)
	{
		transitions[i] = (char **)malloc(sizeof(char)*MAX_INPUT_SIZE*numinps);
		for (j = 0; j<numinps; j++)
		{
			transitions[i][j] = (char *)malloc(sizeof(char)*MAX_STATE_SIZE);
			printf("\n( %s , %s ) => ", states[i], inputs[j]);
			scanf(" %s", temp_state);
			strcpy(transitions[i][j], temp_state);
		}
	}
	printf("Enter the initial state of DFA: ");
	scanf(" %s",initial_state);
	printf("Enter the number of final states in the DFA: ");
	scanf("%d",&num_final_states);
	printf("Enter the final states: ");
	for(i=0;i<num_final_states;i++)
	{
		scanf("%s",temp_state);
		strcpy(final_states[i],temp_state);	
	}
	printf("Enter a String to find ID: ");
	scanf(" %s", id_string);
	strcpy(cur_state, initial_state);
	for (i = 0; i<strlen(id_string); i++)
	{
		cur_inp[0] = id_string[i];
		cur_inp[1] = '\0';
		row_id = get_id(cur_inp, inputs, numinps);
		if (row_id == -1)
		{
			printf("Input symbol is not present in sigma");
			return 0;
		}
		col_id = get_id(cur_state, states, numstates);
		strcpy(cur_state, transitions[col_id][row_id]);
		printf("\n---- %s => %s ----\n", cur_inp, cur_state);
	}
	if(get_id(cur_state,final_states,num_final_states) != -1)
		printf("The string is accepted!");
	else
		printf("The string is NOT accepted!");
}