Kruskal's algorithm

  • Produces minimum spanning tree, MST (aka minimum connector).
  • An MST is such that the total length of its arcs is as small as possible.


  • Kruskal's algorithm:
    • Sort all the arcs into ascending order of weight.
    • Select the arc of least weight to start the tree.
    • Consider the next arc of least weight. If their is a choice of equal arcs, consider each in turn.
      • If it would form a cycle with the arcs already selected, reject it.
      • If it does not form a cycle, add it to the tree.
    • Repeat step 3 until all vertices are connected