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

#define ARR_A_LEN 5
#define ARR_B_LEN 7

void fill(uint8_t* arr, size_t len, uint8_t value)
{
    for(size_t i = 0; i < len; ++i)
        arr[i] = value;
}

void print(const uint8_t* arr, size_t len)
{
    for(size_t i = 0; i < len; ++i)
        printf("%zu: %u\n", i, arr[i]);
}

int main(void)
{   
    uint8_t big_array[ARR_A_LEN + ARR_B_LEN];
    uint8_t* arr_a = big_array;
    uint8_t* arr_b = big_array + ARR_A_LEN;
	// (1)
    fill(arr_a, ARR_A_LEN, 23);
    fill(arr_b, ARR_B_LEN, 11);
    print(big_array, ARR_A_LEN + ARR_B_LEN);
}