Compilare: user.cpp: In function ‘void dfs2(int, const string&, std::vector<int>&, std::vector<std::vector<int> >&, std::vector<int>&, std::vector<bool>&)’: user.cpp:43:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( ; j < fii[i].size() && vals[fii[i][j]] != ch; ++j); ^ user.cpp:44:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j == fii[i].size()){ ^ user.cpp:48:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = j+1; k < fii[i].size(); ++k){ ^