Compilare: user.cpp: In function ‘int main()’: user.cpp:455:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (Find(G[x], y) == G[x].size()) { ^ user.cpp:423:22: warning: unused variable ‘i’ [-Wunused-variable] int op, x, y, D, i; ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:45:52: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, BUFFER_SIZE, 1, file); ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:18:48: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, BUFFER_SIZE, 1, file); ^