Graphs and Network Algorithms · Shortest Paths

Dijkstra's Algorithm

Dijkstra's algorithm finds shortest paths from one source when edge weights are nonnegative.

Student Focus

Students learn the algorithm as a careful extension of BFS with weighted distances.

Guided Lesson Notes

How Code Scholars teaches Dijkstra's Algorithm

This guide helps students understand the idea, implement it carefully, explain the runtime, and recognize when the pattern belongs in a larger problem.

In a session, students usually start with a small trace, then write or review code, then test edge cases. The final step is a short explanation: what the structure or algorithm stores, why it is correct, and what changes when the input grows.

Key Ideas

  • Distance estimates
  • Priority queue frontier
  • Nonnegative-weight requirement

Practice Prompts

  • Trace Dijkstra on a weighted graph.
  • Explain why a priority queue improves the next-node choice.

Tutoring Connection

Turn the topic into usable problem-solving skill

Students can use this page before a lesson, after a difficult homework assignment, or while preparing for AP Computer Science A extensions, Advanced Topics in CS, USACO growth, or a college data structures course.