"Network Algorithms"

Question 1

What is the primary purpose of Dijkstra’s Algorithm?

It solves a fundamental network problem.

Answer 1

To find the shortest path (or minimum cost path) from a given origin node to all other nodes in a network.

It builds a “shortest path tree” rooted at the origin.

Question 2

What is the key difference in how Dijkstra’s and A* select the next node to explore?

Answer 2

Dijkstra’s uses the one with the least cost from the origin. A* uses the cost from the origin PLUS an estimated cost to the destination.

This heuristic guides A* towards the goal, making it faster.

Question 3

Why was the A* algorithm developed as an alternative to Dijkstra’s?

It addresses a specific weakness.

Answer 3

Because Dijkstra’s can be prohibitively slow for certain large networks.

A* is often described as a “guided” or “informed” search.