/in/foo.c: In function 'main':
/in/foo.c:5:9: warning: zero-length gnu_printf format string [-Wformat-zero-length]
  printf("");
         ^~
/in/foo.c:15:10: warning: too many arguments for format [-Wformat-extra-args]
   printf("Yes",a);
          ^~~~~
/in/foo.c:19:10: warning: too many arguments for format [-Wformat-extra-args]
   printf("No",a);
          ^~~~