Compilare: user.cpp: In function ‘int main()’: user.cpp:19:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size() - 1; ++i) { ^ user.cpp:108:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size() - 1; ++i) { ^ user.cpp:23:18: warning: unused variable ‘ok8’ [-Wunused-variable] bool ok = 0, ok8 = 0, ok10 = 0; ^ user.cpp:23:27: warning: unused variable ‘ok10’ [-Wunused-variable] bool ok = 0, ok8 = 0, ok10 = 0; ^