Compilare: user.cpp: In function ‘std::vector<int> dfs_up_to(int)’: user.cpp:32:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < tmp.size(); ++i) ~~^~~~~~~~~~~~ user.cpp:37:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] (l-init_val[cur] < ret.size() ? ret[l-init_val[cur]] : 0); ~~~~~~~~~~~~~~~~^~~~~~~~~~~~ user.cpp:39:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] (l-final_val[cur] < ret.size() ? ret[l-final_val[cur]] : 0); ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~ user.cpp:41:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ret.size() == l+1 - init_val[cur]) ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~ user.cpp:43:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(l+1 - init_val[cur] < ret.size()) ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:74:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(tmp2.size() < l+1) curr_res = 0; ~~~~~~~~~~~~^~~~~