运行 ID: 20771

Main.cc: In function ‘int main()’:
Main.cc:7:20: warning: format ‘%lf’ expects argument of type ‘double’, but argument 2 has type ‘int’ [-Wformat=]
  printf("%.2lf",ans)
                    ^
Main.cc:8:2: error: expected ‘;’ before ‘cout’
  cout<