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:80:9: warning: variable 'sol' set but not used [-Wunused-but-set-variable] int sol; ^~~