my Turing machine set to repeat 0 1

s_tm.c

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>


#define BLANK ' '
#define ONE   '1'
#define ZERO  '0'

#define TO_RIGHT 1
#define TO_LEFT -1


#define STATE_COUNT 5


typedef struct
{

    char next_state_name;

    int direction;

    bool write;

    char write_value; 

} state_when;

typedef struct
{

    char name;

    state_when *when_b;
    state_when *when_o;
    state_when *when_z;

} state;


state_when b = { 'c', TO_RIGHT, true , ZERO  };
state_when c = { 'e', TO_RIGHT, false, BLANK };
state_when e = { 'f', TO_RIGHT, true , ONE   };
state_when f = { 'b', TO_RIGHT, false, BLANK };


state b_state = { 'b', &b, NULL, NULL };
state c_state = { 'c', &c, NULL, NULL };
state e_state = { 'e', &e, NULL, NULL };
state f_state = { 'f', &f, NULL, NULL };

state end_state = { '\0', NULL, NULL, NULL };


int tape_length = 0;

char *tape = NULL;

int tape_offset = 0;

int control_head_position = 0;


state states[STATE_COUNT];

state current_state;


int main(int argc, char *argv[])
{

    states[0] = b_state;
    states[1] = c_state;
    states[2] = e_state;
    states[3] = f_state;
    
    states[4] = end_state;


    current_state = b_state;


    tape_length = 64;

    tape = (char *)malloc(tape_length * sizeof(char));

    tape_offset = tape_length / 2;


    memset(tape, ' ', tape_length * sizeof(char));


    while (tape_offset + control_head_position < tape_length)
    {

        char value_read = tape[tape_offset + control_head_position];


        state_when state_now;


        switch (value_read)
        {

        case BLANK:

            state_now = *current_state.when_b;

            break;

        case ONE  :

            state_now = *current_state.when_o;
        
            break;
        
        case ZERO :

            state_now = *current_state.when_z;

            break;

        }


        if (state_now.write)
        {

            tape[tape_offset + control_head_position] = state_now.write_value;

        }            

    
        control_head_position += state_now.direction;
    

        for (int i = 0; i < STATE_COUNT; i++)
        {

            if (states[i].name == state_now.next_state_name)
            {

                current_state = states[i];

                break;

            }

        }


        printf("|");
        for (int i = 0; i < tape_length; i++)
            printf("%c|", tape[i]);
        puts("");

    }


    free(tape);


    return 0;

}