Compilare: user.cpp: In function ‘int main()’: user.cpp:37:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(tree_edges.size()<n-1) ^ user.cpp:39:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<edges.size();i++) ^ user.cpp:64:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<tree_edges.size();i++) ^