Compilare: user.cpp: In function ‘bool get_hamiltonian_queries()’: user.cpp:189:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < road.size(); i++) ^ user.cpp: In function ‘bool solve_hamiltonian_query(const hamiltonian_query&)’: user.cpp:236:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < nodes.size(); i++) ^ user.cpp:287:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < nodes.size(); i++) ^ user.cpp: In function ‘bool solve_hamiltonian_queries()’: user.cpp:295:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < queries.size(); i++) ^ user.cpp: In function ‘void print_solution()’: user.cpp:338:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < solution.size(); i++) ^