Compilare: user.cpp: In function ‘int main()’: user.cpp:120:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0;j < vec[i]->nr.size();++j) ^ user.cpp: In function ‘void create_fail_links()’: user.cpp:59:18: warning: iteration 57u invokes undefined behavior [-Waggressive-loop-optimizations] if (!node->c[i]) ^ user.cpp:57:3: note: containing loop for (int i = 0;i < 60;++i) ^