Compilare: main.cpp: In function 'void bfs(int, int)': main.cpp:27:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<nod[a.first].size(); i++) ~^~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:53:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<sol.size(); i++) g << sol[i] << ' '; ~^~~~~~~~~~~