Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:20:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<Be.size();i++){ ^ user.cpp:25:30: error: no matching function for call to ‘std::basic_string<char>::push_back(std::string&)’ B1.push_back(str2); ^ user.cpp:25:30: note: candidate is: In file included from /usr/include/c++/4.8/string:52:0, from /usr/include/c++/4.8/bits/locale_classes.h:40, from /usr/include/c++/4.8/bits/ios_base.h:41, from /usr/include/c++/4.8/ios:42, from /usr/include/c++/4.8/istream:38, from /usr/include/c++/4.8/fstream:38, from user.cpp:1: /usr/include/c++/4.8/bits/basic_string.h:1052:7: note: void std::basic_string<_CharT, _Traits, _Alloc>::push_back(_CharT) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>] push_back(_CharT __c) ^ /usr/include/c++/4.8/bits/basic_string.h:1052:7: note: no known conversion for argument 1 from ‘std::string {aka std::basic_string<char>}’ to ‘char’ user.cpp:27:19: error: statement cannot resolve address of overloaded function str2.clear; ^ user.cpp:32:31: error: no matching function for call to ‘std::basic_string<char>::push_back(std::string&)’ str.push_back(str2); ^ user.cpp:32:31: note: candidate is: In file included from /usr/include/c++/4.8/string:52:0, from /usr/include/c++/4.8/bits/locale_classes.h:40, from /usr/include/c++/4.8/bits/ios_base.h:41, from /usr/include/c++/4.8/ios:42, from /usr/include/c++/4.8/istream:38, from /usr/include/c++/4.8/fstream:38, from user.cpp:1: /usr/include/c++/4.8/bits/basic_string.h:1052:7: note: void std::basic_string<_CharT, _Traits, _Alloc>::push_back(_CharT) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>] push_back(_CharT __c) ^ /usr/include/c++/4.8/bits/basic_string.h:1052:7: note: no known conversion for argument 1 from ‘std::string {aka std::basic_string<char>}’ to ‘char’ user.cpp:34:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<Be.size();i++) { ^ user.cpp:71:1: error: expected ‘}’ at end of input } ^