added example 5.1_5

5.1_5.pl

+% nacteni:
+/* ['5.1_5.pl']. */
+
+:- retractall(start/0).
+:- retractall(write_all_X/3).
+
+?-op(100,xfx,to), dynamic(hanoi/5).
+
+hanoi(1,A,B,_,[A to B]).
+hanoi(N,A,B,C,Moves) :- N>1, N1 is N-1, lemma(hanoi(N1,A,C,B,Ms1)),
+hanoi(N1,C,B,A,Ms2), append(Ms1,[A to B|Ms2],Moves).
+
+lemma(P) :- P,asserta((P :- !)).
+
+% demonstracni vypis
+
+  % abychom se vyhli varovanim "Redefined static procedure ..."
+:- dynamic
+       write_all_X/3,
+       start/0.
+       
+write_all_X(Goal,X,Name):-
+            call(Goal),write('  '),write(Name),write(' = '),write(X),nl,fail.
+write_all_X(_,_,_).
+
+start:- 
+    write('Demostrace programu Hanoi'),nl,
+    write('hanoi(+PocetTaliru,+z_tyce,+na_tyc,+pomoci_tyce,-Tahy)'),nl,
+    write('Vysledek dotazu "hanoi(2,a,b,c,M)".'),nl,
+    write_all_X(hanoi(2,a,b,c,M),M,'M'),
+    write('Vysledek dotazu "hanoi(3,a,b,c,M)".'),nl,
+    write_all_X(hanoi(3,a,b,c,M),M,'M'),
+    write('Vysledek dotazu "hanoi(4,a,b,c,M)".'),nl,
+    write_all_X(hanoi(4,a,b,c,M),M,'M').
+?-start.
+
+:- retractall(start/0).
+:- retractall(write_all_X/3).

5.1_5.py

+#!/usr/bin/env python
+# encoding=utf-8 (pep 0263)
+
+from linked_lists import LinkedList, Cons, Nil
+
+hanoi_mem = dict()
+def hanoi(n, a, b, c):
+    if n == 1:
+        return LinkedList(["%s to %s" % (a, b)])
+    if n < 1:
+        raise ValueError("n musi byt kladne")
+    if (n+1, a, c, b) not in hanoi_mem:
+        hanoi_mem[(n-1, a, c, b)] = hanoi(n-1, a, c, b)
+    if (n+1, a, c, b) not in hanoi_mem:
+        hanoi_mem[(n-1, c, b, a)] = hanoi(n-1, c, b, a)
+    ms1 = hanoi_mem[(n-1, a, c, b)]
+    ms2 = hanoi_mem[(n-1, c, b, a)]
+    return append(ms1, Cons("%s to %s" % (a, b), ms2))
+
+def append(xs, ys):
+    if xs == Nil:
+        return ys
+    else:
+        return Cons(xs.head, append(xs.tail, ys))
+
+# demonstracni vypis
+if __name__ == "__main__":
+    print("Demonstrace programu Hanoi")
+    print("hanoi(pocet_taliru, z_tyce, na_tyc, pomoci_tyce)")
+
+    print("\nVysledek dotazu hanoi(2, 'a', 'b', 'c'): ")
+    print(hanoi(2, 'a', 'b', 'c'))
+
+    print("\nVysledek dotazu hanoi(3, 'a', 'b', 'c'): ")
+    print(hanoi(3, 'a', 'b', 'c'))
+
+    print("\nVysledek dotazu hanoi(4, 'a', 'b', 'c'): ")
+    print(hanoi(4, 'a', 'b', 'c'))

5.1_5.py.out

+Demonstrace programu Hanoi
+hanoi(pocet_taliru, z_tyce, na_tyc, pomoci_tyce)
+
+Vysledek dotazu hanoi(2, 'a', 'b', 'c'): 
+['a to c', 'a to b', 'c to b']
+
+Vysledek dotazu hanoi(3, 'a', 'b', 'c'): 
+['a to b', 'a to c', 'b to c', 'a to b', 'c to a', 'c to b', 'a to b']
+
+Vysledek dotazu hanoi(4, 'a', 'b', 'c'): 
+['a to c', 'a to b', 'c to b', 'a to c', 'b to a', 'b to c', 'a to c', 'a to b', 'c to b', 'c to a', 'b to a', 'c to b', 'a to c', 'a to b', 'c to b']