Compilare: main.cpp: In function 'void bfs(int)': main.cpp:20:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[vf].size();i++){ ~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:35:9: warning: iteration 99998 invokes undefined behavior [-Waggressive-loop-optimizations] v[i]=-1; ~~~~^~~ main.cpp:34:16: note: within this loop for(int i=1;i<=NN;i++) ~^~~~