Eroare de compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:36:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x].size();++i) ~^~~~~~~~~~~~ user.cpp: In function ‘ll solve(std::vector<str>&)’: user.cpp:83:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<w.size();++i) ~^~~~~~~~~ user.cpp:115:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<w.size();++i) ~^~~~~~~~~ user.cpp:119:43: error: no match for ‘operator[]’ (operand types are ‘str’ and ‘int’) lca+=1ll*x.val*(pr[hi]-pr[x.i])*(x[i]!=0)*(pr[x.i-1]-(lo!=0)*pr[lo-1]); ^