Compilare: user.cpp: In function ‘void read(int&)’: user.cpp:24: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp:34: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp:49: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp:57: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp: In function ‘int main()’: user.cpp:158: warning: comparison between signed and unsigned integer expressions user.cpp:126: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:127: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:132: warning: ‘x’ may be used uninitialized in this function user.cpp:132: warning: ‘y’ may be used uninitialized in this function