Compilare: user.cpp: In function ‘void read()’: user.cpp:62: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:63: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:67: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void BFS()’: user.cpp:80: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void BFS_back()’: user.cpp:118: warning: comparison between signed and unsigned integer expressions