FizzBuzz with goto

goto.c

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

/*

```bash
gcc goto.c
./a.out
```

*/

int main(void) {
  const int MAX = 100;
  int i = 1;
  char text[256];

loop:
  goto append_fizz; append_fizz_end:
  goto append_buzz; append_buzz_end:
  goto set_number; set_number_end:
  goto print; print_end:
  goto clear_text; clear_text_end:
  goto goto_end; goto_end_end:
  goto increment_counter; increment_counter_end:
  goto loop;

append_fizz:
  if (i % 3 == 0) strcat(text, "Fizz");
  goto append_fizz_end;

append_buzz:
  if (i % 5 == 0) strcat(text, "Buzz");
  goto append_buzz_end;

set_number:
  if (text[0] == '\0') sprintf(text, "%d", i);
  goto set_number_end;

print:
  printf("%s\n", text);
  goto print_end;

clear_text:
  text[0] = '\0';
  goto clear_text_end;

goto_end:
  if (MAX < i) goto end;
  goto goto_end_end;

increment_counter:
  i++;
  goto increment_counter_end;

end:
  return 0;
}

goto2.c

#include <stdio.h>

#define MAX_SIZE 256

int main(void) {
  const int MAX = 100;
  int i = 1;
  char text1[MAX_SIZE];
  char text2[MAX_SIZE];
  int append_type;
  int unused_var;

loop:
  goto append_fizz; append_fizz_end:
  goto append_buzz; append_buzz_end:
  goto set_number; set_number_end:
  goto print; print_end:
  goto clear_text; clear_text_end:
  goto goto_end; goto_end_end:
  goto increment_counter; increment_counter_end:
  goto loop;

append_fizz:
  if (0 == i % 3) {
    text2[0] = 'F';
    text2[1] = 'i';
    text2[2] = 'z';
    text2[3] = 'z';
    text2[4] = '\0';
    append_type = 1;
    goto strcat; strcat_append_fizz_end:
    unused_var = 1;
  }
  goto append_fizz_end;

append_buzz:
  if (0 == i % 5) {
    text2[0] = 'B';
    text2[1] = 'u';
    text2[2] = 'z';
    text2[3] = 'z';
    text2[4] = '\0';
    append_type = 2;
    goto strcat; strcat_append_buzz_end:
    unused_var = 1;
  }
  goto append_buzz_end;

set_number:
  if ('\0' == text1[0]) sprintf(text1, "%d", i);
  goto set_number_end;

print:
  printf("%s\n", text1);
  goto print_end;

clear_text:
  text1[0] = '\0';
  goto clear_text_end;

goto_end:
  if (MAX < i) goto end;
  goto goto_end_end;

increment_counter:
  i++;
  goto increment_counter_end;

strcat:
  for (int j=0; j<MAX_SIZE; j++) {
    if ('\0' == text1[j]) {
      for (int k=0; k<MAX_SIZE; k++) {
        text1[j+k] = text2[k];
      }
      goto strcat_loop_break;
    }
  }
strcat_loop_break:
  if (1 == append_type) goto strcat_append_fizz_end;
  if (2 == append_type) goto strcat_append_buzz_end;

end:
  return 0;
}

normal.c

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

int main(void) {
  const int MAX = 100;
  int i = 1;
  char text[256];

  while (1) {
    if (i % 3 == 0) strcat(text, "Fizz");
    if (i % 5 == 0) strcat(text, "Buzz");
    if (text[0] == '\0') sprintf(text, "%d", i);
    printf("%s\n", text);
    text[0] = '\0';

    if (MAX < i) {
      break;
    }
    i++;
  }

  return 0;
}