Hata kodu basma

#include <stdio.h>

int main(void) {
  int a = 0;

  if (scanf("%d", &a) == 1){
    printf("number\n");
  }
  else{
    printf("not number\n");
  }
 
  return 0;
}

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

#define MAX_INPUT 100

int main(void) {
  char str[MAX_INPUT] = "";
  int flag = 0;

  scanf("%s", str);

  for (int i = 0; i < strlen(str); ++i){
    if (!isdigit(str[i])){
      printf("not number\n");
      ++flag;
    }
  }

  if (flag == 0){
    printf("number\n");
  }

  return 0;
}