Compilare: main.cpp: In function 'int main()': main.cpp:48:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++) ~^~~~~~~~~~~~~~ main.cpp:63:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++) ~^~~~~~~~~~~~~~ main.cpp:79:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<ok.size();i++) ~^~~~~~~~~~ main.cpp:83:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<ans.size();i++) ~^~~~~~~~~~~