2. Fill in the table below with the populated prev vector and the distances from each vertex to vertex 4. For each vertex i (except vertex 4), compare the distance d(4,i) with the distance d(4,prev[i]). What do you notice? Why does this make sense? i |0|1 2 3 4 5 prev[i] -1 d(4,i) 0 d(4,prev[i]) 5 0 } 4 BFS: part 3 1 2 3 // pre: from < n(), to < n() std::vector Graph::shortestPath (int from, int to) { } std::queue std::vector visited (n(), 0); std::vector prev (n(), -1); 5 visited [from] q.push (from); } while (q. size() > 0) { int cur = q. front (); q.pop(); for (auto neighbor : adjLists_[cur]) { if (!visited [neighbor]) { = cur; } // HERE = cur q; true; prev [neighbor] visited [neighbor] q.push (neighbor); std::vector output; = int cur to; while (cur != from) { output.push_back (cur); prev[cur]; } return output; = true;