Eroare de compilare: user.cpp: In function ‘bool valid(long long int)’: user.cpp:22:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v.size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:46:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<v.size(); i++) { ^ user.cpp:48:3: error: reference to ‘begin’ is ambiguous begin.insert(s); ^ user.cpp:17:17: note: candidates are: std::set<long long int> begin set <long long> begin, sol; ^ In file included from /usr/local/include/c++/4.8.0/bits/basic_string.h:42:0, from /usr/local/include/c++/4.8.0/string:52, from /usr/local/include/c++/4.8.0/bits/locale_classes.h:40, from /usr/local/include/c++/4.8.0/bits/ios_base.h:41, from /usr/local/include/c++/4.8.0/ios:42, from /usr/local/include/c++/4.8.0/ostream:38, from /usr/local/include/c++/4.8.0/iostream:39, from user.cpp:1: /usr/local/include/c++/4.8.0/initializer_list:89:5: note: template<class _Tp> constexpr const _Tp* std::begin(std::initializer_list<_Tp>) begin(initializer_list<_Tp> __ils) noexcept ^ In file included from /usr/local/include/c++/4.8.0/string:51:0, from /usr/local/include/c++/4.8.0/bits/locale_classes.h:40, from /usr/local/include/c++/4.8.0/bits/ios_base.h:41, from /usr/local/include/c++/4.8.0/ios:42, from /usr/local/include/c++/4.8.0/ostream:38, from /usr/local/include/c++/4.8.0/iostream:39, from user.cpp:1: /usr/local/include/c++/4.8.0/bits/range_access.h:87:5: note: template<class _Tp, unsigned int _Nm> _Tp* std::begin(_Tp (&)[_Nm]) begin(_Tp (&__arr)[_Nm]) ^ /usr/local/include/c++/4.8.0/bits/range_access.h:58:5: note: template<class _Container> decltype (__cont.begin()) std::begin(const _Container&) begin(const _Container& __cont) -> decltype(__cont.begin()) ^ /usr/local/include/c++/4.8.0/bits/range_access.h:48:5: note: template<class _Container> decltype (__cont.begin()) std::begin(_Container&) begin(_Container& __cont) -> decltype(__cont.begin()) ^ user.cpp:54:6: error: reference to ‘begin’ is ambiguous if(begin.find(s) != begin.end()) sol.insert(s); ^ user.cpp:17:17: note: candidates are: std::set<long long int> begin set <long long> begin, sol; ^ In file included from /usr/local/include/c++/4.8.0/bits/basic_string.h:42:0, from /usr/local/include/c++/4.8.0/string:52, from /usr/local/include/c++/4.8.0/bits/locale_classes.h:40,