Compilare: user.cpp: In member function ‘int Trie::length_com_pref(int, int*, int)’: user.cpp:68:15: warning: unused variable ‘ok’ [-Wunused-variable] int j = 1, ok = 0; ^ user.cpp:58:8: warning: unused variable ‘q’ [-Wunused-variable] Node *q = t; ^ user.cpp:60:6: warning: unused variable ‘mx’ [-Wunused-variable] int mx = -1; ^ user.cpp: In function ‘int main()’: user.cpp:102:10: warning: unused variable ‘f’ [-Wunused-variable] int e, f; ^ user.cpp:90:6: warning: unused variable ‘op’ [-Wunused-variable] int op; ^