Edexcel D1 2010 January — Question 2

Exam BoardEdexcel
ModuleD1 (Decision Mathematics 1)
Year2010
SessionJanuary
TopicMinimum Spanning Trees

2. Prim's algorithm finds a minimum spanning tree for a connected graph.
  1. Explain the terms
    1. connected graph,
    2. tree,
    3. spanning tree.
  2. Name an alternative algorithm for finding a minimum spanning tree. \begin{table}[h]
    CambridgeLondonNorwichOxfordPortsmouthSalisburyYork
    Cambridge (C)-606281132139156
    London (L)60-116567488211
    Norwich (N)62116-144204201181
    Oxford (O)8156144-8463184
    Portsmouth (P)1327420484-43269
    Salisbury (S)139882016343-248
    York (Y)156211181184269248-
    \captionsetup{labelformat=empty} \caption{Figure 2}
    \end{table} Figure 2 shows the distances by road, in miles, between seven cities.
    1. Use Prim's algorithm, starting at London, to find the minimum spanning tree for these cities. You must clearly state the order in which you selected the edges of your tree, and the weight of the final tree.
    2. Draw your tree using the vertices given in Diagram 2 in the answer book.
      (5)