Compilare: main.cpp: In function 'int ok(int)': main.cpp:15:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 15 | for ( i = 0 ; i < check.size () ; ++ i ) | ~~^~~~~~~~~~~~~~~ main.cpp:23:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 23 | if ( pozsir >= pozs [ letter ].size () ) | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:38:10: warning: unused variable 'ch' [-Wunused-variable] 38 | char ch ; | ^~ main.cpp:68:24: warning: 'last' may be used uninitialized in this function [-Wmaybe-uninitialized] 68 | out << last << '\n' ; | ^~~~