/in/foo.cc: In function 'int main()':
/in/foo.cc:11:12: error: 'sort' was not declared in this scope
  sort(a,a+n);
            ^
/in/foo.cc:13:34: error: 'abs' was not declared in this scope
  for(i=0;i<n;i++) ans+=abs(a[i]-t);
                                  ^