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Topic summary · Student revision

Algorithms on Graphs Topic Review summary

Self-review on graph algorithms: Kruskal, Prim, Dijkstra, and network terminology for D1.

Files: Topic-Review-Algorithms-on-Graphs.pdf · Topic-Review-Algorithms-on-Graphs-Answers.pdf · free public downloads · diagrams in the PDFs

Key learning points

  • Trees, cycles, and connectedness — know definitions cold.
  • Kruskal: add shortest edges that do not form a cycle (sort edges first).
  • Prim: grow a tree from a start vertex by adding the cheapest link out.
  • Dijkstra: shortest paths in a network with non-negative weights.
  • State the order you add edges/vertices — method marks depend on it.

Worked example 1 — Kruskal cue

When does Kruskal reject an edge?

Working

WhenitwouldcreateacycleWhen it would create a cycle

Otherwise take the next shortest.

Worked example 2 — Dijkstra

What does a permanent label represent?

Working

ShortestdistancefromthestartconfirmedShortest distance from the start confirmed

Temporary labels may still improve.

Worked example 3 — Practice point 1

Apply this idea from the Topic Review: Trees, cycles, and connectedness — know definitions cold.

Working

see answers PDF\text{see answers PDF}

Attempt without notes, then check the answers PDF.

Worked example 4 — Practice point 2

Apply this idea from the Topic Review: Kruskal: add shortest edges that do not form a cycle (sort edges first).

Working

see answers PDF\text{see answers PDF}

Attempt without notes, then check the answers PDF.

Scaffolded Learning Sheet and answers (PDFs)

This page is a short, searchable overview for revision and search engines. Use the Scaffolded Learning Sheet first, then the Answers PDF for a full written solution. The printable PDFs remain the main classroom resource.