11. Write a Prolog program to implement maxlist(List,Max) so that Max is the greatest number in the list of numbers List.
max([H|T],R):-
length(T,L),
L>0 -> ( max(T,R1), ( H > R1 -> R is H ; R is R1 ) ) ; R is H.
OUTPUT:
max([6,9,7],X).
X = 9
max([6,9,70],X).
X = 70
10. Write a Prolog program to implement max(X,Y,Max) so that Max is the greater of two numbers X and Y.
max(X,Y,R):-
X>=Y ->
R is X,
write(R)
;
R is Y,
write(R).
OUTPUT:
max(2,6,X).
6
X = 6
12. Write a Prolog program to implement sumlist(List,Sum) so that Sum is the sum of a given list of numbers List.
sumlist([],0).
sumlist([H|T],R):-
sumlist(T,R1),
R is H+R1.
OUTPUT:
sumlist([6,9,70],X).
X = 85
14. Write a Prolog program to implement reverse(List,ReversedList) that reverses lists.
reverse([],[]).
reverse([X|T],REV):-reverse(T,R),append(R,[X],REV).
OUTPUT:
reverse([1,2,2],X).
X = [2, 2, 1]
13. Write a Prolog program to implement two predicates evenlength(List) and oddlength(List) so that they are true if their argument is a list of even or odd length respectively.
evenlength:-
write('true --> even').
oddlength:-
write('true --> odd').
oddeven([_|T]):- length(T,L), L>=0 -> ( L1 is L+1, L2 is mod(L1,2), L2=:=0 ->evenlength ; oddlength ).
OUTPUT:
oddeven([5,8,9]).
true
--> odd
1true
oddeven([5,8,6,9]).
true
--> even
1true
8. Write a Prolog program to implement append for two lists.
app([],L,L).
app([X|M],N,[X|Q]):-
app(M,N,Q).
OUTPUT:
app([1,2],[3,4],X).
X = [1, 2, 3, 4]
app([1,2],[],X).
X = [1, 2]
7. Write a Prolog program, remove-nth(Before, After) that asserts the After list is the Before list with the removal of every n‘th item from every list at all levels.
del(1,[_|T],T).
del(P,[X|Y],[X|R]):-
P1 is P-1,
del(P1,Y,R).
dalpos(P,L,R):-
P1 is P-1,
del(P1,L,R1),
del(P,R1,R).
OUTPUT:
del(2,[10,20,30,40],X).
X = [10, 30, 40]
Next101001,000 Stop
9. Write a Prolog program to implement palindrome (List).
pal([]):- write('palindrome').
pal([_]):- write('palindrome').
pal(L) :-
append([H|T], [H], L),
pal(T) ;write('Not a palindrome').
OUTPUT:
pal([1,2,1]).
palindrome
1true
Next101001,000 Stop
pal([1,2,2]).
Not
a palindrome
1true
6. Write a Prolog program to remove the Nth item from a list.
del(1,[_|T],T).
del(P,[X|Y],[X|R]):-
P1 is P-1,
del(P1,Y,R).
OUTPUT:
del(2,[1,2],X).
X = [1]
Next101001,000 Stop
del(3,[1,2,3,4],X).
X = [1, 2, 4]
Next101001,000 Stop
del(5,[1,2,3,4],X).
false
5. Write a prolog program, insert_nth(item, n, into_list, result) that asserts that result is the list into_list with item inserted as the n‘th element into every list at all levels.
insert_nth(Item,1,List,[Item|List]).
insert_nth(Item,Pos,[H|List],[H|Result]):-Pos1 is Pos-1,insert_nth(Item,Pos1,List,Result).
OUTPUT:
