## 7.4 Exercises

Exercise 7.1 (See solution)

> Magic Sequence

> A magic sequence of length is a sequence

> of integers such that for every

> - is an integer between 0 and .

> - the number occurs exactly times in the sequence.

> Write a parameterized script that, given , can enumerate all magic sequences of length .

> The script should use the procedure

> > `{FD.exactly` K`` S`` I`}`

> that creates a propagator for the constraint saying that exactly K fields of the record S are equal to the integer I.

> You can drastically reduce the search space of the script by having propagators for the redundant constraints

> and

> Explain why these constraints are redundant.