Compilare: main.cpp: In function 'bool Check(int)': main.cpp:36:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<vec[nod].size(); i++) ~^~~~~~~~~~~~~~~~ main.cpp:53:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<vec[i].size(); j++) ~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:91:15: warning: 'sol' may be used uninitialized in this function [-Wmaybe-uninitialized] Check(sol); ^