#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

struct display {
  uint8_t data_pin;
  uint8_t lacth_pin;
  uint8_t clock_pin;

  uint8_t indicators_num;
  uint8_t first_cathode_pin;
  uint8_t* indicator_state;

};

struct display display_create(uint8_t data_pin, uint8_t lacth_pin, uint8_t clock_pin, uint8_t indicators_num, uint8_t first_cathode_pin) {

    uint8_t* indicator_state = malloc( sizeof(uint8_t) * indicators_num );

    struct display main_display = {data_pin, lacth_pin, clock_pin, indicators_num, first_cathode_pin, indicator_state};

    for(uint8_t i = 0; i < indicators_num; i++) {
        main_display.indicator_state[i] = 0;
    }

    return main_display;
}

void show_number(struct display* main_display, int number ) {

    for(uint8_t i = 0; i < main_display -> indicators_num; i++) {

        main_display -> indicator_state[i] = number % 10;

        digitalWrite(main_display -> latchPin, LOW);
        shiftOut( main_display -> data_pin, main_display -> clock_pin, LSBFIRST,  main_display -> indicator_state[i] );
        digitalWrite(main_display -> latchPin, HIGH);

        number /= 10;
    }

}

int main() {

    struct display main_display = display_create(2,3,4,4,5);

    int number = 13;
    show_number(&main_display, number);

}