Compilare: user.cpp: In function ‘bool cmp(std::string, std::string)’: user.cpp:17:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i<str2.size()&&j<str1.size(); i++) ^ user.cpp:17:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i<str2.size()&&j<str1.size(); i++) ^ user.cpp:20:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return (j == str1.size()); ^ user.cpp: In function ‘int main()’: user.cpp:49:7: warning: unused variable ‘ok’ [-Wunused-variable] bool ok; ^