module.cpp: In function 'void read_input()': module.cpp:20: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result module.cpp:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result module.cpp:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result module.cpp: In function 'void write_output()': module.cpp:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result module.cpp: In function 'void get_rec_modules(const std::vector<int, std::allocator<int> >&, const std::vector<int, std::allocator<int> >&, int, std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > >*)': module.cpp:140: warning: comparison between signed and unsigned integer expressions module.cpp:143: warning: comparison between signed and unsigned integer expressions module.cpp:148: warning: comparison between signed and unsigned integer expressions module.cpp:194: warning: comparison between signed and unsigned integer expressions module.cpp:197: warning: comparison between signed and unsigned integer expressions module.cpp:199: warning: comparison between signed and unsigned integer expressions module.cpp: In function 'void get_modules(const std::vector<int, std::allocator<int> >&, int, std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > >*)': module.cpp:219: warning: comparison between signed and unsigned integer expressions module.cpp: In function 'void dfs(int, const std::vector<int, std::allocator<int> >&, std::vector<int, std::allocator<int> >*)': module.cpp:267: warning: comparison between signed and unsigned integer expressions module.cpp: In function 'void get_connected_components(const std::vector<int, std::allocator<int> >&, std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > >*)': module.cpp:278: warning: comparison between signed and unsigned integer expressions module.cpp: In function 'int num_modules(const std::vector<int, std::allocator<int> >&)': module.cpp:311: warning: comparison between signed and unsigned integer expressions module.cpp:312: warning: comparison between signed and unsigned integer expressions module.cpp:333: warning: comparison between signed and unsigned integer expressions module.cpp:337: warning: comparison between signed and unsigned integer expressions module.cpp:356: warning: comparison between signed and unsigned integer expressions module.cpp:372: warning: comparison between signed and unsigned integer expressions module.cpp:376: warning: comparison between signed and unsigned integer expressions module.cpp:379: warning: comparison between signed and unsigned integer expressions module.cpp:382: warning: comparison between signed and unsigned integer expressions module.cpp:411: warning: comparison between signed and unsigned integer expressions