View Compilation Error

0_0_30379001_19705.cpp: In function 'int main()':
0_0_30379001_19705.cpp:6:5: error: 'cin' was not declared in this scope
     cin >> T;
     ^
0_0_30379001_19705.cpp:10:31: error: 'scanf' was not declared in this scope
             scanf("%lf", &p[i]);
                               ^
0_0_30379001_19705.cpp:12:30: error: 'sort' was not declared in this scope
         sort(p + 1, p + n + 1);
                              ^
0_0_30379001_19705.cpp:14:35: error: 'printf' was not declared in this scope
             printf("%.10f\n", p[n]);
                                   ^
0_0_30379001_19705.cpp:26:35: error: 'printf' was not declared in this scope
             printf("%.10f\n", ans2);
                                   ^