Compilare: main.cpp: In member function 'bool Hash::operator+=(char)': main.cpp:31:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ main.cpp: In function 'bool isOk(std::vector<int>, int)': main.cpp:48:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < v.size(); i++) ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:92:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < s.size(); j++) ~~^~~~~~~~~~