Eroare de compilare: user.cpp: In function ‘void oui(int)’: user.cpp:7:20: error: ‘a’ was not declared in this scope for(int i=1;i<=a;i++) ^ user.cpp:8:9: error: ‘s’ was not declared in this scope s+=pow(i,i); ^ user.cpp:9:9: error: ‘s’ was not declared in this scope s%=10; ^ user.cpp:10:12: error: return-statement with a value, in function returning 'void' [-fpermissive] return s; ^ user.cpp: In function ‘int main()’: user.cpp:17:10: warning: statement has no effect [-Wunused-value] for(n; n>=1; n--) ^ user.cpp:22:10: error: no match for ‘operator<<’ (operand types are ‘std::ofstream {aka std::basic_ofstream<char>}’ and ‘void’) g<<oui(h)<<endl; ^ In file included from /usr/include/c++/5/istream:39:0, from /usr/include/c++/5/sstream:38, from /usr/include/c++/5/complex:45, from /usr/include/c++/5/ccomplex:38, from /usr/include/x86_64-linux-gnu/c++/5/32/bits/stdc++.h:52, from user.cpp:1: /usr/include/c++/5/ostream:108:7: note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__ostream_type& (*)(std::basic_ostream<_CharT, _Traits>::__ostream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>] operator<<(__ostream_type& (*__pf)(__ostream_type&)) ^ /usr/include/c++/5/ostream:108:7: note: no known conversion for argument 1 from ‘void’ to ‘std::basic_ostream<char>::__ostream_type& (*)(std::basic_ostream<char>::__ostream_type&) {aka std::basic_ostream<char>& (*)(std::basic_ostream<char>&)}’ /usr/include/c++/5/ostream:117:7: note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__ios_type& (*)(std::basic_ostream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>; std::basic_ostream<_CharT, _Traits>::__ios_type = std::basic_ios<char>] operator<<(__ios_type& (*__pf)(__ios_type&)) ^ /usr/include/c++/5/ostream:117:7: note: no known conversion for argument 1 from ‘void’ to ‘std::basic_ostream<char>::__ios_type& (*)(std::basic_ostream<char>::__ios_type&) {aka std::basic_ios<char>& (*)(std::basic_ios<char>&)}’ /usr/include/c++/5/ostream:127:7: note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>] operator<<(ios_base& (*__pf) (ios_base&)) ^ /usr/include/c++/5/ostream:127:7: note: no known conversion for argument 1 from ‘void’ to ‘std::ios_base& (*)(std::ios_base&)’ /usr/include/c++/5/ostream:166:7: note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>] operator<<(long __n) ^ /usr/include/c++/5/ostream:166:7: note: no known conversion for argument 1 from ‘void’ to ‘long int’ /usr/include/c++/5/ostream:170:7: note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>] operator<<(unsigned long __n) ^ /usr/include/c++/5/ostream:170:7: note: no known conversion for argument 1 from ‘void’ to ‘long unsigned int’ /usr/include/c++/5/ostream:174:7: note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(bool) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>] operator<<(bool __n) ^ /usr/include/c++/5/ostream:174:7: note: no known conversion for argument 1 from ‘void’ to ‘bool’