Compilare: user.cpp: In function ‘int Find(const std::vector<int>&, int)’: user.cpp:92:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < from.size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:467:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (Find(G[x], y) == G[x].size()) { ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:19:48: 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); ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:46:52: 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); ^