Compilare: user.cpp: In function ‘int dfs(int)’: user.cpp:15:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<L[nod].size();i++){ ^ user.cpp:32:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘void drum(int, int)’: user.cpp:37:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<L[nod].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:63:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] L[x].push_back (y); ^ user.cpp:64:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] u[y]++; ^ user.cpp:77:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] X[ch] = ch; ^