Compilare: user.cpp: In function ‘int get_int()’: user.cpp:85:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (; p < strlen (s); ++p) ^ user.cpp: In function ‘int main()’: user.cpp:129:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k=0; k<S[j].size(); ++k) ^ user.cpp:137:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k=0; k<S[i].size(); ++k) ^ user.cpp:149:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k=0; k<S[i].size(); ++k) ^