Integer array

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

struct Integer{
    uint64_t length;
    uint64_t *data;    
};

void integer_print(Integer a)
{
    for(uint64_t i = 0; i < a.length; ++i)
    {
        uint64_t pos = a.length - 1 - i;
        printf("%.16llX", a.data[pos]);
    }
    printf("\n");
}

int main() {
    Integer a = {3, (uint64_t *)calloc(3, 8)};

    a.data[0] = 0xF333F333F333F333;
    a.data[1] = 0xD222D222D222D222;
    a.data[2] = 0xA111A111A111A111;
    integer_print(a);
    
    return 0;
}