/in/foo.cc: In function 'int main()':
/in/foo.cc:16:27: warning: unknown conversion type character 0xa in format [-Wformat=]
  printf("%.2lf%\n",a/n*100);
                           ^
/in/foo.cc:17:27: warning: unknown conversion type character 0xa in format [-Wformat=]
  printf("%.2lf%\n",b/n*100);
                           ^
/in/foo.cc:18:27: warning: unknown conversion type character 0xa in format [-Wformat=]
  printf("%.2lf%\n",c/n*100);
                           ^
/in/foo.cc:19:27: warning: unknown conversion type character 0xa in format [-Wformat=]
  printf("%.2lf%\n",d/n*100);
                           ^