View Compilation Error

0_0_38332195_28783.cpp: In function 'int main()':
0_0_38332195_28783.cpp:4:8: error: 'cin' was not declared in this scope
  while(cin>>n){
        ^
0_0_38332195_28783.cpp:12:3: error: 'cout' was not declared in this scope
   cout.setf(ios::fixed);
   ^
0_0_38332195_28783.cpp:12:13: error: 'ios' has not been declared
   cout.setf(ios::fixed);
             ^
0_0_38332195_28783.cpp:13:23: error: 'setprecision' was not declared in this scope
   cout<<setprecision(2)<<a[1]<<endl;
                       ^
0_0_38332195_28783.cpp:13:32: error: 'endl' was not declared in this scope
   cout<<setprecision(2)<<a[1]<<endl;
                                ^