Compilare: user.cpp: In function ‘int main()’: user.cpp:14:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < s[i].size(); j++) ^ user.cpp:24:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < s[i].size(); j++) ^