Compilare: main.cpp: In function 'void FILL(int, int, int)': main.cpp:53:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int it2 = 0; it2 < v[viz[x][y]].size(); ++it2) ~~~~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int DFS(int)': main.cpp:78:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v[nod].size(); ++i) ~~^~~~~~~~~~~~~~~ main.cpp:87:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ main.cpp: In function 'void FILL(int, int, int)': main.cpp:36:30: warning: iteration 8 invokes undefined behavior [-Waggressive-loop-optimizations] int x = i + di[it]; ~~~~~^ main.cpp:34:29: note: within this loop for (int it = 0; it < 9; ++it) ~~~^~~