Question

Prolog questions. Thanks!

Write a predicate that removes consecutive duplicate elements from a list. ?- remove_consecutive_duplicates ([a, a, b, c, c, a, a, a, e, d, d, a, c], L). L = [a, b, c,,a, e, d, a, c].

Answer 1

Below is your prolog predicate. Let me know if you have any issue in comments.

% remove_consecutive_duplicates(L1,L2) :- the list L2 is obtained from the list L1 by
% removing repeated occurrences of elements into a single copy
% of the element.
% (list,list) (+,?)

remove_consecutive_duplicates([],[]).
remove_consecutive_duplicates([X],[X]).
remove_consecutive_duplicates([X,X|Xs],Zs) :- remove_consecutive_duplicates([X|Xs],Zs).
remove_consecutive_duplicates([X,Y|Ys],[X|Zs]) :- X \= Y, remove_consecutive_duplicates([Y|Ys],Zs).

Sample Run: -

% remove-consecutive-duplicates(L1,し2) :-the list L2 is obtained from the list L1 removing repeated occurrences of elements into a single copy of the element. (List, List +,?) remove_consecutive_duplicates([],[n). remove_consecutive_duplicates(X),[X]) remove_ consecutive duplicates ([x,x Xs],zs)- remove consecutive duplicates ([XIXs] remove_ consecutive_duplicates ([X,YlYs], [xlzs]) -XY, remove_ consecutive duplis 涤 L:[a, b, c, a, e, d, a, c] Next 10 100 1,000 Stop remove_consecutive duplicates([a,a,b,c,c,a,a,a,e,d,d,a,c],L) remove_consecutive_duplicates([a,a,b,c,c,a,a,a,e,d,d,a,cl,L)