Compilare: user.cpp: In function ‘void bron_kerbosch(std::set<int, std::less<int>, std::allocator<int> >&, std::set<int, std::less<int>, std::allocator<int> >&, std::set<int, std::less<int>, std::allocator<int> >&)’: user.cpp:21: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:55: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:56: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:59: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:62: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:75: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result