Compilare: main.cpp: In function 'bool try_to_change(int, int)': main.cpp:15:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod[pos].size();i++) ~^~~~~~~~~~~~~~~~ main.cpp:22:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod[pos].size();i++) ~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:40:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<nod[i].size() && !added[i];j++) ~^~~~~~~~~~~~~~