Compilare: user.cpp: In function ‘void read()’: user.cpp:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void add(int)’: user.cpp:59: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int bfs()’: user.cpp:94: warning: comparison between signed and unsigned integer expressions