Cmpe 220 - Fall 2003

 5th Homework

1- How many weighings of a balanced scale are needed to find a counterfeit coin among eight coins if the counterfeit coin is either heavier or lighter than the others? Describe your method. (Hint: Correct representation will bring you very close to the solution).

2- Let T1 and T2 and T3 be spanning trees of a simple graph G. The distance between Ti and Tj is the number of edges that are in exactly one of them. Show that the distance between T1 and T3 does not exceed the sum of the distance between T1 and T2  and the distance between T2 and T3.

3- Show that if no two edges in a weighted graph have the same weight, then the edge with the least weight incident to a vertex v is included in every minimal spanning tree.

 

Deadline: 19 December 2003, 17:00.