/in/foo.cc: In function 'int main()':
/in/foo.cc:21:30: warning: 'ansr' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<ansl/d<<'\n'<<ansr/d<<'\n';
                              ^~~~
/in/foo.cc:21:16: warning: 'ansl' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<ansl/d<<'\n'<<ansr/d<<'\n';
                ^~~~
/in/foo.cc:17:3: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if(res<=n&&fabs(1.0*i/res-x)<mn) mn=fabs(1.0*i/res-x),ansl=i,ansr=res;
   ^~