Constraint Programming with CP Flashcards
7 cards from real Picat practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Constraint Programming with CP flashcards as text
In Picat's CP module, which predicate is used to declare a list of decision variables with a shared domain?
Answer: Vars :: [Low..High]
The `::` operator with a list on the left and a domain expression on the right constrains all variables in the list to that domain.
What does the `indomain` predicate do when called on a CP variable during search in Picat?
Answer: It assigns the variable each value in its domain on backtracking
`indomain(Var)` non-deterministically instantiates Var to successive values in its domain, supporting backtracking search.
Which global constraint in Picat's CP module enforces that no two variables take the same value?
Answer: all_different/1
`all_different(List)` posts a constraint ensuring every pair of variables in the list has distinct values.
In Picat CP, what is the correct way to post a constraint that X is strictly less than Y?
Answer: X #< Y
Arithmetic constraints on CP variables use the `#` prefix operators such as `#`, `#=`, and `#\=`.
What does `solve(Vars)` do in Picat's CP module?
Answer: Labels all variables in Vars with default search options
`solve(Vars)` triggers constraint propagation and labeling for the given variable list using default strategies.
Which labeling option in Picat's CP `solve` tells the solver to choose the variable with the smallest remaining domain first?
Answer: [ff]
`ff` (fail-first) selects the variable with the fewest remaining domain values, reducing early branching failures.
In Picat CP, what is reification of a constraint?
Answer: Converting a constraint to a boolean variable that is 1 iff the constraint holds
Reification links a boolean (0/1) CP variable to a constraint so the variable equals 1 exactly when the constraint is satisfied.