C (gcc), 113 Bytes

i;main(){while(i++<100){char*h[]={"%d "," "},**p=h;i%3||(*p++="Fizz%2$s");i%5||(*p="Buzz ");printf(*h,i,h[1]);}}

This compiles with several warnings, but no errors.

Here's an ungolfed version with explanations:

/* the following include is omitted; while using printf
   without including it is not conforming to the current
   C standard, with gcc it only generates a warning
   and works flawlessly. Note that omission was valid K&R C */
#include <stdio.h>

/* Declare a global int variable. The golfed code omits the
   type because of the old implicit-int rule, which only
   generates a warning also in modern gcc. Also note that
   global variables without initializer are zero-initialized;
   this is still defined behaviour today. In this ungolfed
   code I've added the implied initializer for clarity. */
int i=0;

/* The main function. Again, the golfed code makes use of the
   old implicit int rule. */
int main()
{
  /* loop up to 100; since we increment before entering the
     loop body, the first number in the loop is 1. */
  while(i++<100)
  {
    /* In this array of two strings, the first will be used as
       format string to a printf later, while the second will
       be the third argument for the same printf. As is, the
       format string will tell printf to format the second
       argument (which will be i) as number, followed by a space.
       The third argument, a single-space string, is ignored
       in that case. */
    char *h[] = { "%d ", " " };

    /* This second variable (which in the golfed version is
       declared in the same declaration as h) points to the first
       entry of h. It is used to change the entries of h, and
       it is separate because pointer arithmetic is used to
       modify different strings depending on the condition. */
    char **p = h;

    /* This is basically an if-not statement. If i%3 is not
       nonzero (that is, if i is divisible by 3), this statement
       replaces the format string with one that prints "Fizz"
       followed by the content of the third argument of printf
       as string, which is the second string in h. At this
       point it contains just a space. Also, when replacing the 
       format string, the pointer p is incremented, so it then
       points to the second element of h. */
    i%3 || (*p++ = "Fizz%2$s");

    /* This if-in-disguise handles divisibility by 5. It stores
       a pointer to "Buzz " into whatever p points to. If i
       is not divisible by 3, this still is the format string,
       so if instructs the following printf to just print "Buzz "
       and ignore any further arguments. Otherwise, p points
       to the final string argument, so that after the "Fizz"
       it prints "Buzz " instead of just a space. */
    i%5 || (*p = "Buzz ");

    /* This finally is the printf statement talked about
       in the previous comments. Note that *h is equivalent
       to h[0] */
    printf(*h,i,h[1]);
  }
}

posted over 3 years ago

CC BY-SA 4.0

3y ago

celtschk‭

1294 reputation 27 43 168 69