Compilare: user.cpp: In function ‘bool in(std::__cxx11::string, std::__cxx11::string)’: user.cpp:45:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < a.size(); ++i) { ^ user.cpp:56:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < b.size(); ++i) { ^ user.cpp:57:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (p >= 0 && (p + 1 >= a.size() || a[p + 1] != b[i])) ^ user.cpp:63:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (p + 1 == a.size()) ^ user.cpp:40:9: warning: unused variable ‘n’ [-Wunused-variable] int p, n = a.size(), m = b.size(); ^ user.cpp:40:23: warning: unused variable ‘m’ [-Wunused-variable] int p, n = a.size(), m = b.size(); ^ user.cpp: In function ‘int main()’: user.cpp:93:34: warning: narrowing conversion of ‘((& v.std::vector<_Tp, _Alloc>::operator[]<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char> > >(((std::vector<std::__cxx11::basic_string<char> >::size_type)j)))->std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size<char, std::char_traits<char>, std::allocator<char> >() - ((std::__cxx11::basic_string<char>::size_type)kmp((* & v.std::vector<_Tp, _Alloc>::operator[]<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char> > >(((std::vector<std::__cxx11::basic_string<char> >::size_type)j))), (* & v.std::vector<_Tp, _Alloc>::operator[]<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char> > >(((std::vector<std::__cxx11::basic_string<char> >::size_type)i))))))’ from ‘std::__cxx11::basic_string<char>::size_type {aka long unsigned int}’ to ‘int’ inside { } [-Wnarrowing] g[i].push_back({j, v[j].size() - kmp(v[j], v[i])}); ^