Compilare: user.cpp: In function ‘void ReadInput()’: user.cpp:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void DFS()’: user.cpp:52: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void ExpandComponents()’: user.cpp:88: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void ConstructTree()’: user.cpp:109: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void DFSTree()’: user.cpp:132: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void WriteAnswer()’: user.cpp:203: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result