View Compilation Error

0_0_33911879_31482.cpp:1:14: error: stray '#' in program
 (int)(16*ans)#include<bits/stdc++.h>
              ^
0_0_33911879_31482.cpp:1:2: error: expected unqualified-id before 'int'
 (int)(16*ans)#include<bits/stdc++.h>
  ^
0_0_33911879_31482.cpp:1:2: error: expected ')' before 'int'
0_0_33911879_31482.cpp: In function 'double f(long long int)':
0_0_33911879_31482.cpp:25:31: error: 'powf' was not declared in this scope
         ans=ans+1.0/(powf(16,k)*(8.0*(k+n-1)+x));
                               ^
0_0_33911879_31482.cpp: In function 'int main()':
0_0_33911879_31482.cpp:32:25: error: 'scanf' was not declared in this scope
     while(~scanf("%d",&T))
                         ^
0_0_33911879_31482.cpp:41:42: error: 'printf' was not declared in this scope
             printf("Case #%d: %lld ",kk,n);
                                          ^