(Hospitals) Let G=(V,E) be a directed graph. We interpret a subset of nodes HV as hospitals, and the remaining nodes V\H as houses. Determine for each house vV\H a hospital h[v]H that is reachable from v, or determine that there is no hospital reachable from v (in this case we set h[v]= ). a. Assume that there is exactly one hospital (i.e., H=1 ). Solve the problem in time O(n+m). b. Solve the problem in time O(n+m) without any restriction on H