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:21:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ( pozsir >= pozs [ check [ i ] - 'a' ].size () ) ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:42:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < big.size () ; ++ i ) ~~^~~~~~~~~~~~~ main.cpp:61:24: warning: 'last' may be used uninitialized in this function [-Wmaybe-uninitialized] out << last << '\n' ; ^~~~