Compilare: user.cpp: In function ‘int main()’: user.cpp:68:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secvmax.in", "r", stdin); ^ user.cpp:69:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secvmax.out", "w", stdout); ^ user.cpp: In function ‘int fastRead_int()’: user.cpp:56:17: warning: ‘c’ is used uninitialized in this function [-Wuninitialized] while(c < '0' || c > '9') ^ user.cpp: In function ‘int main()’: user.cpp:56:17: warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:53:17: note: ‘c’ was declared here register char c; ^ user.cpp:56:17: warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] while(c < '0' || c > '9') ^ user.cpp:53:17: note: ‘c’ was declared here register char c; ^