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