/in/foo.cc: In function 'int main()':
/in/foo.cc:10:2: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
  else
  ^~~~
/in/foo.cc:11:30: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'else'
      cout<<"登录失败！";{
                              ^