Compilare: user.cpp: In function ‘void query(node*)’: user.cpp:194:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j, x, y; ^ user.cpp:194:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, x, y; ^ user.cpp:194:15: warning: unused variable ‘x’ [-Wunused-variable] int i, j, x, y; ^ user.cpp:194:18: warning: unused variable ‘y’ [-Wunused-variable] int i, j, x, y; ^ user.cpp: In function ‘int main()’: user.cpp:228:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("votare.out","w",stdout); ^ user.cpp: In member function ‘void Buffer::refill()’: user.cpp:58:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(&data[0], 1, dim, stdin); ^ user.cpp: In constructor ‘Buffer::Buffer(std::string, int)’: user.cpp:22:46: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(name.c_str(), "r", stdin); ^