View Compilation Error

0_0_34472596_17595.cpp: In function 'int main()':
0_0_34472596_17595.cpp:6:5: error: 'ios' has not been declared
     ios::sync_with_stdio(false);
     ^
0_0_34472596_17595.cpp:7:5: error: 'cin' was not declared in this scope
     cin.tie(0);cout.tie(0);
     ^
0_0_34472596_17595.cpp:7:16: error: 'cout' was not declared in this scope
     cin.tie(0);cout.tie(0);
                ^
0_0_34472596_17595.cpp:9:18: error: 'scanf' was not declared in this scope
     scanf("%d",&T);
                  ^
0_0_34472596_17595.cpp:19:15: error: 'fixed' was not declared in this scope
         cout<<fixed<<setprecision(10)<<ans<<endl;
               ^
0_0_34472596_17595.cpp:19:37: error: 'setprecision' was not declared in this scope
         cout<<fixed<<setprecision(10)<<ans<<endl;
                                     ^
0_0_34472596_17595.cpp:19:45: error: 'endl' was not declared in this scope
         cout<<fixed<<setprecision(10)<<ans<<endl;
                                             ^