Compilare: user.cpp: In function ‘int solve1()’: user.cpp:17:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < N.size() ; ++i) ^ user.cpp: In function ‘bool subsir(std::string, std::string)’: user.cpp:26:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < s2.size() && lg != s1.size() ; ++i) ^ user.cpp:26:52: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < s2.size() && lg != s1.size() ; ++i) ^ user.cpp:29:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(lg == s1.size()) ^