Compilare: main.cpp: In constructor 'Graf::Graf(int, int, int, int)': main.cpp:23:18: warning: 'Graf::z' will be initialized after [-Wreorder] int n, x, y, z; ^ main.cpp:20:25: warning: 'std::vector<std::vector<int> > Graf::adj' [-Wreorder] vector <vector <int> > adj; ^~~ main.cpp:25:2: warning: when initialized here [-Wreorder] Graf(int n, int x, int y, int z) : n(n), x(x), y(y), z(z), adj(n + 1), siz(n + 1) {} ^~~~ main.cpp: In member function 'P Graf::dfs(int, int)': main.cpp:84:19: warning: statement has no effect [-Wunused-value] res.z == true; ~~~~~~^~~~~~~ main.cpp: At global scope: main.cpp:125:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] main() ^