Section 1 Worksheet Solutions: CSPs

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Published on Jun 30, 2024 This response is partially generated with the help of AI. It may contain inaccuracies.

Table of Contents

Step-by-Step Tutorial: Section 1 Worksheet Solutions: CSPs

Formulating a CSP for Scheduling Professors to Classes:

  1. Identify the entities involved: classes and professors.
  2. Determine the variables and values: Classes are the variables and Professors are the values.
  3. Define unary constraints: Professors cannot teach every class.
  4. Establish binary constraints: Classes cannot overlap in scheduling.

Creating a Constraint Graph for the CSP:

  1. Draw a node for each variable (class).
  2. Connect nodes with edges representing constraints between classes.
  3. Ensure all constraints are included in the graph.

Trapped Pac-Man Description:

  1. Identify the variables (corridors) and values (pit, ghost, exit).
  2. Establish constraints:
    • Pac-Man can feel a breeze between corridors.
    • Neighboring corridors cannot both be exits.

Implementing Forward Checking:

  1. Start with unary constraints.
  2. Assign a value to a variable and check neighboring variables for consistency.
  3. Prune values that violate constraints.
  4. Repeat for all variables until a solution is found or backtrack if needed.

Applying MRV (Minimum Remaining Values) Heuristic:

  1. Choose the variable with the fewest remaining values to assign next.
  2. Consider constraints to eliminate invalid assignments.
  3. Deduce possible solutions based on constraints.

Solving CSP Using Tree Structure:

  1. Linearize the tree from any node as the root.
  2. Perform a backward pass to check consistency of parent-child arcs.
  3. If a variable has an empty domain, backtrack to the cut-set variable.
  4. Conduct a forward pass to reach a solution without backtracking.

Backtracking Behavior in CSP:

  1. Backtrack only on assigning values to the cut-set variable (x1).
  2. Explore all branches efficiently using the tree CSP algorithm.
  3. Enforce consistency to ensure valid solutions without unnecessary backtracking.

By following these steps, you can effectively solve CSPs and tackle complex scheduling and logical problems efficiently.