Compilare: user.cpp: In function ‘void _read()’: user.cpp:13: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:14: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, 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:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void divide(std::vector<int, std::allocator<int> >&, int)’: user.cpp:30: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void _write()’: user.cpp:72: warning: comparison between signed and unsigned integer expressions user.cpp:76: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:85: warning: unused variable ‘sgd’ user.cpp:85: warning: unused variable ‘m’