foo.cc: In function 'void solve(double, double)':
foo.cc:12:21: warning: format '%f' expects a matching 'double' argument [-Wformat=]
  else printf(" %.2f");return;}
                     ^
foo.cc:12:2: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
  else printf(" %.2f");return;}
  ^~~~
foo.cc:12:23: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
  else printf(" %.2f");return;}
                       ^~~~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。