Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:28:53: error: no match for ‘operator!=’ (operand types are ‘std::set<int>::iterator {aka std::_Rb_tree_const_iterator<int>}’ and ‘int’) if(sume_part.find(sumpart - v[i] - v[j] - v[k]) != NULL && v[i] + v[j] + v[k] < sumpart) ^ user.cpp:28:53: note: candidates are: In file included from /usr/local/include/c++/4.8.0/set:60:0, from user.cpp:3: /usr/local/include/c++/4.8.0/bits/stl_tree.h:302:7: note: bool std::_Rb_tree_const_iterator<_Tp>::operator!=(const _Self&) const [with _Tp = int; std::_Rb_tree_const_iterator<_Tp>::_Self = std::_Rb_tree_const_iterator<int>] operator!=(const _Self& __x) const ^ /usr/local/include/c++/4.8.0/bits/stl_tree.h:302:7: note: no known conversion for argument 1 from ‘int’ to ‘const _Self& {aka const std::_Rb_tree_const_iterator<int>&}’ In file included from /usr/local/include/c++/4.8.0/iosfwd:40:0, from /usr/local/include/c++/4.8.0/ios:38, from /usr/local/include/c++/4.8.0/ostream:38, from /usr/local/include/c++/4.8.0/iostream:39, from user.cpp:2: /usr/local/include/c++/4.8.0/bits/postypes.h:221:5: note: template<class _StateT> bool std::operator!=(const std::fpos<_StateT>&, const std::fpos<_StateT>&) operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs) ^ /usr/local/include/c++/4.8.0/bits/postypes.h:221:5: note: template argument deduction/substitution failed: In file included from /usr/include/stdlib.h:33:0, from /usr/local/include/c++/4.8.0/cstdlib:72, from /usr/local/include/c++/4.8.0/ext/string_conversions.h:41, from /usr/local/include/c++/4.8.0/bits/basic_string.h:2817, 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:2: user.cpp:28:56: note: ‘std::set<int>::iterator {aka std::_Rb_tree_const_iterator<int>}’ is not derived from ‘const std::fpos<_StateT>’ if(sume_part.find(sumpart - v[i] - v[j] - v[k]) != NULL && v[i] + v[j] + v[k] < sumpart) ^ In file included from /usr/local/include/c++/4.8.0/bits/stl_algobase.h:64:0, from /usr/local/include/c++/4.8.0/bits/char_traits.h:39, from /usr/local/include/c++/4.8.0/ios:40, from /usr/local/include/c++/4.8.0/ostream:38, from /usr/local/include/c++/4.8.0/iostream:39, from user.cpp:2: /usr/local/include/c++/4.8.0/bits/stl_pair.h:227:5: note: template<class _T1, class _T2> constexpr bool std::operator!=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&) operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) ^ /usr/local/include/c++/4.8.0/bits/stl_pair.h:227:5: note: template argument deduction/substitution failed: In file included from /usr/include/stdlib.h:33:0, from /usr/local/include/c++/4.8.0/cstdlib:72, from /usr/local/include/c++/4.8.0/ext/string_conversions.h:41, from /usr/local/include/c++/4.8.0/bits/basic_string.h:2817, from /usr/local/include/c++/4.8.0/string:52, from /usr/local/include/c++/4.8.0/bits/locale_classes.h:40,