Alma and Gustav are arguing over whether the following algorithm computes a shortest path from start to target for an undirected weighted graph with non-negative weights. Help fuel settle their debate: Either prove that it does, or give a counterexample, in which case prove that yours is a counterexample. Input: Vertices, adjacency lists, edge weights, start, target. Q:= new min-heap Q.insert(start,0) start.visited := false for each vertex v + start: Q.insert(0, 0) v.visited := false while Q not empty: U := Q.extract-min() u.visited := true for each z in u's adjacency list: if (not z.visited) and weight(u, 2)