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

#define NUM_RUNS 500


void fizzbuzz_normal ()
{
    int i, a, b;

    for (i = 1; i <= 100; i++)
    {
        a = i % 5;
        b = i % 3;

        if (a && b)
            printf("%d\n", i);
        else if (a)
            puts("fizz");
        else if (b)
            puts("buzz");
        else
            puts("fizzbuzz");
    }
}

void fizzbuzz_normal_15 ()
{
    int i, a, b;

    for (i = 1; i <= 100; i++)
    {
        if (i % 15)
            printf("%d\n", i);
        else if (i % 5)
            puts("fizz");
        else if (i % 3)
            puts("buzz");
        else
            puts("fizzbuzz");
    }
}

void fizzbuzz_buffered ()
{
    int i, a, b;

    char buffer[9 * 100 + 1];
    char* ptr = buffer;

    for (i = 1; i <= 100; i++)
    {
        a = i % 5;
        b = i % 3;

        if (a && b)
            ptr += sprintf(ptr, "%d\n", i);
        else if (a)
        {
            strcpy(ptr, "fizz\n");
            ptr += 5;
        }
        else if (b)
        {
            strcpy(ptr, "buzzz\n");
            ptr += 5;
        }
        else
        {
            strcpy(ptr, "fizzbuzz\n");
            ptr += 9;
        }
    }

    fputs(buffer, stdout);
}

typedef void (*func_t)();

void time_func (double* out, func_t func)
{
    clock_t start, end;

    start = clock();
    int i;
    for (i = 0; i < NUM_RUNS; i++)
        func();
    end = clock();

    *out = (end - start) / (double)CLOCKS_PER_SEC;
}

int main ()
{
    double time_normal,
           time_normal_15,
           time_buffered;

    time_func(&time_normal, fizzbuzz_normal);
    time_func(&time_normal_15, fizzbuzz_normal_15);
    time_func(&time_buffered, fizzbuzz_buffered);

    printf("\n"
           "results:\n"
           "  normal             %.4fs\n"
           "  normal (i %% 15)    %.4fs\n"
           "  buffered           %.4fs\n",
        time_normal,
        time_normal_15,
        time_buffered);
}