Automata sim C

// Alphabet A B C D E X
// Strings to be recognized
// String 1: CABED
// String 2: ABBACCA
// String 3: ECADE
// String 4: ADACE

#include <stdio.h>

int automata_1(char c, int state);
int automata_2(char c, int state);
int automata_3(char c, int state);
int automata_4(char c, int state);

#define STATE_AUTOMATA_1_END 5
#define STATE_AUTOMATA_2_END 7
#define STATE_AUTOMATA_3_END 5
#define STATE_AUTOMATA_4_END 5

int main() {
  char user_input;
  int state_automata_1 = 0,
      state_automata_2 = 0,
      state_automata_3 = 0,
      state_automata_4 = 0;

  do {
    // Input character
    user_input = getchar();
    // Clearing input buffer
    getchar();

    // Exec and check automata 1
    state_automata_1 = automata_1(user_input, state_automata_1);
    if (state_automata_1 == STATE_AUTOMATA_1_END) {
      printf("Riconosciuta CABED\n");
    }

    // Exec and check automata 2
    state_automata_2 = automata_2(user_input, state_automata_2);
    if (state_automata_2 == STATE_AUTOMATA_2_END) {
      printf("Riconosciuta ABBACCA\n");
    }

    // Exec and check automata 3
    state_automata_3 = automata_3(user_input, state_automata_3);
    if (state_automata_3 == STATE_AUTOMATA_3_END) {
      printf("Riconosciuta ECADE\n");
    }

    // Exec and check automata 4
    state_automata_4 = automata_4(user_input, state_automata_4);
    if (state_automata_4 == STATE_AUTOMATA_4_END) {
      printf("Riconosciuta ADACE\n");
    }

    // printf(
    //     "Current states: \n"
    //     "Automata 1: %d"
    //     "Automata 2: %d"
    //     "Automata 3: %d"
    //     "Automata 4: %d\n",
    //     state_automata_1, state_automata_2, state_automata_3, state_automata_4
    // );

  } while (user_input != 'X');

  return 0;
}

int automata_1(char c, int state) {
  // C, 0
  // A, 1
  // B, 2
  // E, 3
  // D, 4
  if ((c == 'C' && state == 0) || (c == 'A' && state == 1) ||
      (c == 'B' && state == 2) || (c == 'E' && state == 3) ||
      (c == 'D' && state == 4)) {
    return state + 1;
  }

  return 0;
}

// ABBACCA
int automata_2(char c, int state) {
  if ((c == 'A' && state == 0) || (c == 'B' && state == 1) ||
      (c == 'B' && state == 2) || (c == 'A' && state == 3) ||
      (c == 'C' && state == 4) || (c == 'C' && state == 5) ||
      (c == 'A' && state == 6)) {
    return state + 1;
  }

  return 0;
}

// ECADE
int automata_3(char c, int state) {
  if ((c == 'E' && state == 0) || (c == 'C' && state == 1) ||
      (c == 'A' && state == 2) || (c == 'D' && state == 3) ||
      (c == 'E' && state == 4)) {
    return state + 1;
  }

  return 0;
}

// ADACE
int automata_4(char c, int state) {
  if ((c == 'A' && state == 0) || (c == 'D' && state == 1) ||
      (c == 'A' && state == 2) || (c == 'C' && state == 3) ||
      (c == 'E' && state == 4)) {
    return state + 1;
  }

  return 0;
}