Get base, simple, non-acurate function

I've wrote a function to get a number string in some arbitrary bases.

I claim that this function is not accurate.


Here's the source code:

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

void getBase(int num, int base, char* string);
char numbers[] = {'0', '1', '2', '3',
                  '4', '5', '6', '7',
                  '8', '9', 'A', 'B',
                  'C', 'D', 'E', 'F'};

int
main (int argc, char *argv[])
{
    char str[32];

    getBase(2, 2, str);
    printf("%s\n", str);

    getBase(255, 16, str);
    printf("%s\n", str);


    getBase(769878, 10, str);
    printf("%s\n", str);


    return 0;
}

void getBase(int n, int b, char* str)
{
    const size_t SIZE = 32;
    char arr[32+1]={0}; int digits=SIZE, i;
    char* ptr = arr;
    while (n > 0)
    {
        int t = n%b;
        n/=b;
        arr[--digits] = numbers[t];
    }
    while ( *ptr == '\0') ptr++;

    strcpy(str, ptr);
}