Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:56:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<qr[nod].size(); i++){ ^ user.cpp:66:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<g[nod].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:75:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbvalmax.out","w",stdout); ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:13:47: 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); ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:35:51: 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); ^