增加汉诺塔的每次迭代 - PROLOG

Question

我做了这个 hanoi 算法，现在我想递增每次迭代并打印它。谁能帮忙？谢谢！

这是我尝试过的：

increase(X,Y):-Y is X+1.

hanoi(N):-move(N,left,middle,right,0).
move(0,_,_,_,_):-!.
move(N,A,B,C,NUM):- M is N-1,increase(NUM,NUM1),
                    move(M,A,C,B,NUM1),
                    print(A,B,NUM1),
                    increase(NUM1,NUM2),
                    move(M,C,B,A,NUM2).

print(A,B,M):- write(M),
               write(': MOVE DISK FROM '),
               write(A),
               write(' TO '),
               write(B),nl.

我希望它看起来像这样，例如：

?-hanoi(2).
1: MOVE DISK FROM left TO right
2: MOVE DISK FROM left TO middle
3: MOVE DISK FROM right TO middle

但数字显示顺序错误：

?- hanoi(2).
2: MOVE DISK FROM left TO right
1: MOVE DISK FROM left TO middle
3: MOVE DISK FROM right TO middle
true.

Answer 1

来自 Simply Logical https://www.cs.bris.ac.uk/~flach/SL/SL.pdf 的 Hanoi 然后添加了一个单独的打印谓词。

:-op(900,xfx,'TO').
% hanoi(N,A,B,C,Moves) <- Moves is the list of moves to
% move N disks from peg A to peg C,
% using peg B as intermediary peg
hanoi(0,A,B,C,[]).
hanoi(N,A,B,C,Moves):-
  N1 is N-1,
  hanoi(N1,A,C,B,Moves1),
  hanoi(N1,B,A,C,Moves2),
  append(Moves1,[A 'TO' C|Moves2],Moves).

print_hanoi(Size):-
  hanoi(Size,left,middle,right,Moves),
  length(Moves,L),
  numlist(1,L,Is),
  maplist(print_row,Is,Moves).

print_row(I,M):-
  format("~w. MOVE DISK FROM ~w\n",[I,M]).

查询：

 ?- print_hanoi(3).
 1. MOVE DISK FROM left TO right
 2. MOVE DISK FROM left TO middle
 3. MOVE DISK FROM right TO middle
 4. MOVE DISK FROM left TO right
 5. MOVE DISK FROM middle TO left
 6. MOVE DISK FROM middle TO right
 7. MOVE DISK FROM left TO right

增加汉诺塔的每次迭代 - PROLOG

Increment each iteration in tower of hanoi - PROLOG

prolog

towers-of-hanoi