Compilare: main.cpp: In function 'void adaugare(std::__cxx11::string, nod*)': main.cpp:26:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int f = 0 ; f < a.size() ; f ++) ~~^~~~~~~~~~ main.cpp: In function 'void stergere(std::__cxx11::string, nod*)': main.cpp:49:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int f = 0 ; f < a.size() ; f ++) ~~^~~~~~~~~~ main.cpp: In function 'int nr_apar(std::__cxx11::string, nod*)': main.cpp:63:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int f = 0 ; f < a.size() && curent && curent -> prefix > 0 ; f ++) ~~^~~~~~~~~~ main.cpp: In function 'int nr_pref(std::__cxx11::string, nod*)': main.cpp:79:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(f = 0 ; f < a.size() && curent && curent -> prefix > 0 ; f ++) ~~^~~~~~~~~~