fizzBuzz.c

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

static const size_t sizeToAlloc = sizeof("9223372036854775807");

char** fizzBuzz(int n, int* returnSize) {
    char** ret = calloc(n, sizeof(char*));
    *returnSize = n;

    char* sp;
    for (int i = 1; i <= n; ++i) {
        sp = *(ret + (i - 1)) = calloc(1, sizeToAlloc);
        (i % 5 && i % 3) ? sprintf(sp, "%d", i) : sprintf(sp, "%s%s", (i % 3) ? "" : "Fizz", (i % 5) ? "" : "Buzz");
    }

    return ret;
}

int main() {
    int n = 15;
    int returnSize;
    char **res = fizzBuzz(n, &returnSize);
    for (int i = 0; i < n; ++i) {
        printf("%s\n", res[i]);
        free(res[i]);
    }
    free(res);
    return 0;
}