#include <stdio.h>

int is_divisible_by(int dividend, int divisor) {
  return (dividend % divisor) == 0;
}

int puts_no_newline(const char *message) {
  return fputs(message, stdout);
}

int main(void) {
  int counter;
  for (counter = 1; counter <= 100; counter++) {
    if (is_divisible_by(counter, 3)) {
      if (is_divisible_by(counter, 5)) {
        puts_no_newline("FizzBuzz ");
      } else {
        puts_no_newline("Fizz ");
      }
    } else {
      if (is_divisible_by(counter, 5)) {
        puts_no_newline("Buzz ");
      } else {
        printf("%d ", counter);
      }
    }
  }
  return 0;
}

Voilà, est-ce suffisamment lisible maintenant?