Homework # 10
due Tuesday, April 12, 3:30 PM

Parameters

Do exercise 6 on page 384 by completing the Java program ParameterTest.java from a skeleton in $CLASSHOME/src/homework10/: but skip 6(d) (macro expansion). Don't hard-code the values expected into the parameter classes!

Answer the following questions in a file README:

• There is more than one possibility for value-result parameters. Why?
• Why does it not make sense to implement macro-expansion in the test?

Prolog Programs

• Write a Prolog predicate insert that places an element somewhere in a list:

  
  ?- insert(A,[B,C,D],L).
  L = [A, B, C, D] ;
  L = [B, A, C, D] ;
  L = [B, C, A, D] ;
  L = [B, C, D, A] ;
  No
  

• Write a Prolog predicate permute that returns true if the first list is a permutation of the second:

  
  ?- permute([a,b,c],[a,b,c]).
  Yes
  ?- permute([a,b,c],[b,c,a]).
  Yes
  ?- permute([a,b,c],[a,b,a,c]).
  No
  ?- permute([a,b,c],[c,b]).
  No
  

  The permute predicate should use insert as well as being recursive.

• Write a 2x2 Sudoku solver. (If you don't know Sudoku, please look it up.)

  
  ?- X=[[1,_,_,_],
  |     [_,2,1,_],
  |     [_,_,3,_],
  |     [_,_,_,4]], sudoku2(X).
  
  X = [[1, 3, 4, 2], [4, 2, 1, 3], [2, 4, 3, 1], [3, 1, 2, 4]] ;
  
  No
  

  (Here the No shows that the solution given is unique.)

  The sudoku predicate should be defined entirely using the permute predicate.

The code for all predicates should go into homework10.pl in your homework10 directory of your AFS volume.

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