Fibonacci

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

void printarr(int *ptr, size_t num);
int * fibonacci(int *ptr, size_t num);

int main()
{
    int myarr[5] = {1, 2, 3, 4, 5};
    size_t size = sizeof(myarr)/sizeof(int);
    //printf("%Lu", size);
    size_t i = 0;
    int *ptr = myarr;

    printf("SRC\n");
    printarr(ptr, size);

    *ptr = fibonacci(ptr, size);
    printf("DIST\n");
    printarr(ptr, size);

    return 0;
}

void printarr(int *ptr, size_t num){
    size_t i = 0;
    for (; i < num; i++){
        printf("%Lu : %d\n", i, *(ptr + i));
    }
}

int* fibonacci(int *ptr, size_t num){
    size_t i = 2;
    for (i; i < num; i++){
        *(ptr + i) = *(ptr + i - 1) + *(ptr + i - 2);
    }
    return *ptr;
}