Puzzle solvers and other utilities developed with Prolog.
Implemented using SWI-Prolog version 6.6.4 for amd64.
Non generic implementation of a solver for the coins problem (ballance puzzle), allowed to work with and only with twelve coins, finding the coin whit different weight.
In this implementation, consider that the representation of a coin is the list with the format [coin_index, coin_weight, coins_definition], and that the coins options are the static list [n,h,l], where n is normal, h is heaviest and l is lighter.
Call the find_different_coin/3 predicate, informing a list with the coins weight, and returning the position of the different coin and its definition:
?- find_different_coin([2,2,2,2,2,2,2,2,9,2,2,2], Position, Definition).Solver implementation for boolean satisfability problem using non chronological backtracking (bakcjumping) technique.
In this implementation, the logical formula is in CNF format, but only supports OR(v) logic operation. Consider that every atom is represented like x1, x2, x3, ..., xN, a negation is ~ and came before an atom name and the OR operation is #. Every logical expression need to be between parenthesis.
Call the sat/1 predicate informing a CNF formula quoted, corresponding with the representation descripted above:
?- sat("(x1 # x2) # (~x1)").The output it will be printed in the console, informing the total time execution, number of atom instantiations and if the logic formula is sat (true) or unsat (false).
Buil a truth table according the number of variables informed (doesn't supports propositional logic formulas).
Call the build_truth_table/2 informing the number of variables to be used:
?- build_truth_table(5, Columns).The output it will be a list with lists, where each one represents a column of the table.