Compilare: user.cpp: In member function ‘void Task::dfs(int, std::stack<int>&, std::vector<std::vector<int> >&)’: user.cpp:47:38: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if (low[u] >= idx[i] && parent[i] || !parent[i]) { user.cpp:35:28: warning: unused variable ‘j’ [-Wunused-variable] int childrens = 0, j, z; ^ user.cpp: In member function ‘void Task::print_output(std::vector<std::vector<int> >)’: user.cpp:84:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < result.size(); i++) { ~~^~~~~~~~~~~~~~~ user.cpp:85:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < result[i].size(); j++) ~~^~~~~~~~~~~~~~~~~~