Compilare: main.cpp: In member function 'int Solution::min_reachable(int, int, std::vector<std::vector<int> >&, int, std::unordered_map<int, int>&, std::unordered_map<int, std::vector<int> >&, std::vector<std::vector<int> >&)': main.cpp:16:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<lista_adiacenta[root].size();i++ ){ ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:85:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<answer.size();i++){ ~^~~~~~~~~~~~~~ main.cpp:86:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j= 0; j<answer[i].size();j++){ ~^~~~~~~~~~~~~~~~~