Compilare: user.cpp: In function ‘void read(int&)’: user.cpp:21:62: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(cursor == buf_size) fread(buf, 1, buf_size, stdin); ^ user.cpp:28:62: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(cursor == buf_size) fread(buf, 1, buf_size, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:49:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rick.in", "r", stdin); ^ user.cpp:50:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rick.out", "w", stdout); ^ user.cpp:52:35: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, buf_size, stdin); ^