Prolog Examples II(AI,CS409)

Towers of Hanoi Problem

you have N rings of increasing size and three pegs. Initially the three rings are
stacked in order of decreasing size on the first peg. You can move them between pegs but you must never stack a big ring onto a smaller one. What is the sequence of moves to move from all the rings from the first to the the third peg.

answers:

hanoi( N ):- 
      move( N, left, middle, right ).
move(1,X,Y,_) :-
      write('Move top disk from '),
      write(X),
      write(' to '),
      write(Y),
      nl.
move(N,X,Y,Z) :-
      N>1,
      M is N-1,
      move(M,X,Z,Y),
      move(1,X,Y,_),
      move(M,Z,Y,X).

Find Factoria (N!) of a number

factorial(0, 1).                                          % Factorial of 0 is 1.
factorial(N, FactN) :-
    N > 0,                                                      % N is positive
    Nminus1 is N - 1,                                  % Calculate N minus 1
    factorial(Nminus1, FactNminus1), % recursion
    FactN is N * FactNminus1.                % N! = N * (N - 1)!