/* 

  ABC problem in Picat v3.

  From 
  http://rosettacode.org/wiki/ABC_Problem
  """
  You are given a collection of ABC blocks. Just like the ones you had when you were a kid. 
  There are twenty blocks with two letters on each block. You are guaranteed to have a complete alphabet 
  amongst all sides of the blocks. The sample blocks are:

    ((B O) 
    (X K) 
    (D Q) 
    (C P) 
    (N A) 
    (G T) 
    (R E) 
    (T G) 
    (Q D) 
    (F S) 
    (J W) 
    (H U) 
    (V I) 
    (A N) 
    (O B) 
    (E R) 
    (F S) 
    (L Y) 
    (P C) 
    (Z M)) 

   The goal of this task is to write a function that takes a string and can determine whether 
   you can spell the word with the given collection of blocks. The rules are simple:

   Once a letter on a block is used that block cannot be used again
   The function should be case-insensitive
   Show your output on this page for the following words: 

   Example

 
    >>> can_make_word("A")
    True
    >>> can_make_word("BARK")
    True
    >>> can_make_word("BOOK")
    False
    >>> can_make_word("TREAT")
    True
    >>> can_make_word("COMMON")
    False
    >>> can_make_word("SQUAD")
    True
    >>> can_make_word("CONFUSE")
    True
  """

  Cf http://hakank.org/picat/abc_problem.pi (Picat v2)

  This program is ported from the Prolog solution.

  This Picat model was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/


import v3_utils.

main => go.


go ?=>
  abc_problem,
  
  nl.

go => true.


abc_problem :-
  member(Word, ['', 'A', bark, bOOk, treAT, 'COmmon', sQuaD, 'CONFUSE',schoolmastering]),
  abc_problem(Word),
  fail,
  nl.

abc_problem2 :-
	maplist(abc_problem, ['', 'A', bark, bOOk, treAT, 'COmmon', sQuaD, 'CONFUSE',schoolmastering]).
 
 
abc_problem(Word) :-
	L = [[b,o],[x,k],[d,q],[c,p],[n,a],[g,t],[r,e],[t,g],[q,d],[f,s],
	     [j,w],[h,u],[v,i],[a,n],[o,b],[e,r],[f,s],[l,y],[p,c],[z,m]],
 
	(   abc_problem(L, Word)
	->  bp.format('~w OK~n', [Word])
	;   bp.format('~w KO~n', [Word])).
 
abc_problem(L, Word) :-
	bp.atom_chars(Word, C_Words),
	maplist(to_lowercase, C_Words, D_Words),
	can_makeword(L, D_Words).

to_lowercase(C,Lower) :-
  Lower = to_lowercase(C).

can_makeword(_L, []).
 
can_makeword(L, [H | T]) :-
	(   select([H, _], L, L1); select([_, H], L, L1)),
	can_makeword(L1, T).