Compilare: user.cpp: In function ‘int build(int)’: user.cpp:21:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[nod].size(); i++) ^ user.cpp:31:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘void DFS(int)’: user.cpp:37:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0 ;i<v[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:105:21: warning: ‘nod’ may be used uninitialized in this function [-Wmaybe-uninitialized] cop=v[nod][0]; ^