liveBook · Manning

Optimal path

As explained in Grokking AI Algorithms, Second Edition

An optimal path is a sequence of actions or transitions from an initial state to a goal that is best according to the relevant optimization criterion.

An optimal path is a sequence of actions or transitions from an initial state to a goal, chosen as best according to a relevant criterion such as distance. Searching evaluates future states and looks for a path that reaches the goal; changing conditions may require adjusting the plan. section 2.1

A road trip makes the idea intuitive: when a lodge becomes unavailable or time is lost, the route and activities change. The best path is therefore tied to the current situation and goal, not fixed forever. section 2.1

For path problems, the practical challenge is choosing how to search:

  • Represent locations or attractions as nodes and their connections as edges, with distances or other costs attached to paths. section 6.2
  • Compare candidate paths against the optimization criterion, such as total travel distance. section 6.2
  • Recognize that brute force can generate every tour and select the best one, but becomes expensive as the dataset grows. section 6.2

Carnival attractions

For six attractions, one optimal visiting sequence is swings, Ferris wheel, circus, carousel, balloons, and bumper cars. With 15 attractions, the possibilities increase substantially; with 48, brute-force evaluation can take tens of hours. section 6.2

Figure 6.6 Distances between attractions and an optimal path
06_06

Use the diagram to compare path distances and see which complete attraction route is identified as optimal. section 6.2

How Grokking AI Algorithms, Second Edition covers it

How deep it goes
Defines optimal paths and illustrates graph and brute-force reasoning, but defers detailed search algorithms except for an ACO lifecycle reference.
Examples
Uses a changing road trip and a carnival attraction tour with distances, candidate routes, and a selected sequence.
What it assumes
Assumes only an initial state, a goal, and connected states; introduces nodes, edges, distances, tours, and search through examples.
What you can do after
Evaluate candidate routes against a goal and criterion, while recognizing when brute-force search becomes impractical.
How it connects
Connects optimal paths with planning, searching, graphs, brute-force search, and ant colony optimization.

Related concepts

This explainer was generated by Manning's knowledge graph from the text of Grokking AI Algorithms, Second Edition. The section links point to the parts of the book it draws on.