Compilare: user.cpp: In function ‘bool check(std::string&, std::string&)’: user.cpp:13:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < a.size(); ++i) ^ user.cpp: In function ‘int solve()’: user.cpp:25:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(it - i + l >= word.size() || it < i) continue; ^