Compilare: user.cpp: In function ‘void EulerPath(int)’: user.cpp:66:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i != G[node].size() && G[node].size(); ++ i){ ^ user.cpp:68:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(G[node].size() > i && G[node][i] == son) ^ user.cpp:71:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j != G[son].size(); ++ j) ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:20:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:47:47: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^