Compilare: user.cpp:9: warning: integer constant is too large for ‘long’ type user.cpp: In function ‘void read()’: user.cpp:14: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void write()’: user.cpp:65: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result