Compilare: user.cpp: In function ‘int main()’: user.cpp:669:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rev.in", "r", stdin); ^ user.cpp:670:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rev.out", "w", stdout); ^ user.cpp: In member function ‘void Scanner::init(FILE*)’: user.cpp:461:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(input, 1, sizeof(input), fin); ^ user.cpp: In member function ‘void Scanner::ensureCapacity()’: user.cpp:471:51: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(input + size, 1, BUF_SIZE - size, fin); ^