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Finding Factors

Finding Factors

Finding Factors


I need to write a rule to find all the factors of a given number, this is that i have so far:


% "divisible without remainder function"
dwr(X, M) :- 0 is X mod M.

    D is 1,
    findfactors(X, D).

findfactors(X, D):-
    D = X,
    F is X / D,

findfactors(X, D):-
    D < X,
    E is D + 1,
    findfactors(X, E),
    Factor is X / D,
    dwr(X, D), <--------- This line

Notice the marked line, if i have that line there it will fail as soon as it gets to a number which isn't a factor and not return me any results after X, but without that line it will returnX divided by all of the lower numbers.

Is there a way to make it skip the non-factor numbers and still return the factors without failing ?

Or is there a better way to do this ? (I have to do this using recursion).


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