Compilare: user.cpp: In function ‘void dfs(int, int, int)’: user.cpp:139:29: warning: unused variable ‘z’ [-Wunused-variable] int y = get<0>(it), z = get<1>(it), p = get<2>(it); ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:17:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, 4096, fin); ^