Description
Task 3: Heuristic Search Algorithms
Domain: Uniform Random-4-SAT is a family of SAT problems distributions obtained by randomly generating 3-CNF formulae in the following way: For an instance with n=4 variables and k=5 clauses, each of the k clauses is constructed from 3 literals which are randomly drawn from the 2n possible literals (the n variables and their negations) such that each possible literal is selected with the same probability of 1/2n. Clauses are not accepted for the construction of the problem instance if they contain multiple copies of the same literal or if they are tautological (i.e., they contain a variable and its negation as a literal). Each choice of n and k thus induces a distribution of Random-4-SAT instances. Uniform Random-4-SAT is the union of these distributions over all n and k.
Firstly generate your formula for N = 4 and k = 5. Please write your clauses in the text file and each clause should be written in a different line of the text file. Then input the formula to three algorithms.
Implement:
- Variable neighborhood descent : Modify Hill-Climbing Search to switch to a denser neighborhood function when stuck at a local optimum.
- Beam Search : Code for different beam lengths
- Tabu Search : Implement tabu search and find an optimum tabu tenure value for the domain.
Report Format :
- Brief description about the domain:
- State space
- Start node and goal node
III. MOVEGENandGOALTESTalgorithm
- Heuristic functions considered
- Beam search analysis for different beam lengths
- Tabu search for different values of tabu tenure
- Comparison of Variable neighborhood descent, Beam Search, Tabu Search: Nodes explored
by each
Evaluation Criteria:
Correctness: 15 Report: 10 Code Quality: 5