c-01-bits/hallo-welt.c

#include "hallo-welt.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

#ifndef HALLO
#define HALLO "Hallo Welt"
#endif

void hallo_welt(void) { printf(HALLO); }

// use more then one int type
const char *binaerzahl(uint8_t bin) {
  char *str = malloc(sizeof(bin) * 8 +
                     1); // Allocate 8 bits for actual data and 1 Bit for the \0
                         // sign indicating the end of the string
  if (!str)
    return NULL;
  uint8_t bb;
  for (int i = sizeof(bin) * 8 - 1; i >= 0; i--) {
    bb = bin >> i;
    str[i] = (bb % 2 == 1) ? 1 : 0;
    printf("%d", str[i]);
  }
  str[sizeof(bin)] = '\0';
  return str;
}

int getint(void) {
  uint8_t i;
  scanf("%hhu", &i);
  return i;
}

int main(void) { printf("%s", binaerzahl(getint())); }