Compilare: user.cpp: In member function ‘int Trie::length_com_pref(int, int*, int)’: user.cpp:70:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i < vec[mid][s[id][mid] - 'a'].size();++i) ^ user.cpp:73:80: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] if ((vec[mid][s[id][mid] - 'a'][i]->bt[g[j] / 64]) & (1uLL << (g[j] % 64)) == 0uLL) ^ user.cpp:62:8: warning: unused variable ‘q’ [-Wunused-variable] Node *q = t; ^ user.cpp: In function ‘int main()’: user.cpp:108:10: warning: unused variable ‘f’ [-Wunused-variable] int e, f; ^ user.cpp:96:6: warning: unused variable ‘op’ [-Wunused-variable] int op; ^