Compilare: user.cpp: In function ‘void _read()’: user.cpp:10: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:11: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:12: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void prebk(int, int, int*)’: user.cpp:44: warning: extended initializer lists only available with -std=c++0x or -std=gnu++0x user.cpp:44: warning: array subscript is above array bounds