Compilare: main.cpp: In function 'int main()': main.cpp:14:24: warning: passing NULL to non-pointer argument 2 of 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::getline(std::basic_istream<_CharT, _Traits>::char_type*, std::streamsize) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>; std::basic_istream<_CharT, _Traits>::char_type = char; std::streamsize = long int]' [-Wconversion-null] fin.getline(s1,NULL); ^ main.cpp:15:24: warning: passing NULL to non-pointer argument 2 of 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::getline(std::basic_istream<_CharT, _Traits>::char_type*, std::streamsize) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>; std::basic_istream<_CharT, _Traits>::char_type = char; std::streamsize = long int]' [-Wconversion-null] fin.getline(s2,NULL); ^ main.cpp:23:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < strlen(s1); i++) ~~^~~~~~~~~~~~ main.cpp:39:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < strlen(s2); i++) ~~^~~~~~~~~~~~ main.cpp:47:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j == strlen(s1)) ~~^~~~~~~~~~~~~ main.cpp:17:9: warning: unused variable 'poz' [-Wunused-variable] int poz = 0; ^~~