Compilare: user.cpp: In function ‘int main()’: user.cpp:135:83: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int le = 0, ri = (int) graph[it].size() / 2; ri < graph[it].size(); ++le, ++ri) { ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:15:57: 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, sizeof(char), inputFile); ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:25:42: 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, inputFile); ^