15. 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.

 

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.

% 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([H|T]):-
 length(T,L),
 L>=0 ->
 (
  L1 is L+1,
  L2 is mod(L1,2),
  L2=:=0 ->
   evenlength
  ;
   oddlength
 ).

% Output
Prolog program to implement two predicates evenlength(List) and oddlength(List).

14. Write a Prolog program to implement maxlist(List,Max) so that Max is the greatest number in the list of numbers List using cut predicate.

 

Write a Prolog program to implement maxlist(List,Max) so that Max is the greatest number in the list of numbers List using cut predicate.

% Write a Prolog program to implement maxlist(List,Max) so that Max is the 
% greatest number in the list of numbers List using cut predicate.

max2([H],H).
max2([H|T],R):-
 max2(T,M1),
 H>=M1,
 R is H,!.
max2([H|T],R):-
 max2(T,M1),
 H<M1, 
 R is M1.

% Output
Prolog program to implement maxlist(List,Max) using cut predicate.

13. Write a Prolog program to implement palindrome(List).

 

Write a Prolog program to implement palindrome(List).

% Write a Prolog program to implement palindrome(List).

% append is the inbuilt function.

palind([]):- write('palindrome').
palind([_]):- write('palindrome').
palind(L) :-
 append([H|T], [H], L),
 palind(T)
 ;
 write('Not a palindrome').

% Output
Prolog program to implement palindrome(List).

12. Write a Prolog program to implement reverse(List,ReversedList) that reverses lists.

 

Write a Prolog program to implement reverse(List,ReversedList) that reverses lists.

% Write a Prolog program to implement reverse(List,ReversedList) that reverses
% lists.


/* Reverse of the list. */

reverse([H|T],R):-
 length(T,L),
 L>0 ->
 (
  reverse(T,R1),
  /* write(R1), */
  R is H
 )
 ;
 R is H.

% Output
Prolog Program to reverse the elements in the list.

11. Write a Prolog program to implement GCD of two numbers.

 

Write a Prolog program to implement GCD of two numbers.

% Write a Prolog program to implement GCD of two numbers.

/* GCD of two numbers. */
gcd(X,0,X).
gcd(X,Y,Z):- 
 R is mod(X,Y),
 gcd(Y,R,Z).

% Output
Write a Prolog program to implement GCD of two numbers.

10 Write a Prolog program to implement sumlist(List,Sum) so that Sum is the sum of a given list of numbers List.

 

Write a Prolog program to implement sumlist(List,Sum) so that Sum is the sum of a given list of numbers List.

% Write a Prolog program to implement sumlist(List,Sum) so that Sum is the sum of
% a given list of numbers List.

/* Sum of the numbers from the list. */

sumlist([],0).
  
sumlist([H|T],R):-
  sumlist(T,R1),
  R is H+R1.

% Output
Prolog Program to find the sum of numbers in the list.

9. Write a Prolog program to implement maxlist(List,Max) so that Max is the greatest number in the list of numbers List.

 

Write a Prolog program to implement maxlist(List,Max) so that Max is the greatest number in the list of numbers List.

% Write a Prolog program to implement maxlist(List,Max) so that Max is the 
% greatest number in the list of numbers List.


/* Max of n-#.s in a list. */
maxlist([H|T],R):-
 length(T,L),
 L>0 ->
 (
  maxlist(T,R1),
  (
   H > R1 -> 
     R is H
    ;
     R is R1
  )
 ) 
 ;
 R is H.

% Output
Prolog Program to find maximum number in the list of N numbers.

8. Write a Prolog program to implement max(X,Y,Max) so that Max is the greater of two numbers X and Y.

 

Write a Prolog program to implement max(X,Y,Max) so that Max is the greater of two numbers X and Y.

% Write a Prolog program to implement max(X,Y,Max) so that Max is the greater of
% two numbers X and Y.

/* Max of two #.s */

/* without list. */
max(X,Y,R):-
 X>=Y -> 
  R is X, 
  write(R)
 ;
  R is Y,
  write(R).


/* with list. */
grandiose([H|T],R):-
 H>T -> 
  R is H,
  write(R)
  ;
  R is T,
  write(T).

% Output
 Prolog program to implement max(X,Y,Max) so that Max is the greater of two numbers X and Y.

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.

 

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.

% 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.

/*delete a number in the list. */
delte(1,[_|T],T).
delte(P,[X|Y],[X|R]):-
 P1 is P-1,
 delte(P1,Y,R).

/* delete before and after. */
daltob(P,L,R):-
 P1 is P-1,
 delte(P1,L,R1),
 /* delete before. */
 delte(P,R1,R).
 /* delete after. */

% Output
Prolog Program to delete before and after of the nth element in the list.

6. Write a Prolog program to remove the Nth item from a list.

 

Write a Prolog program to remove the Nth item from a list.

% Write a Prolog program to remove the Nth item from a list.

/*delete a number in the list. */
delte(1,[_|T],T).
delte(P,[X|Y],[X|R]):-
 P1 is P-1,
 delte(P1,Y,R).

% Output
                        Prolog program to remove the Nth item from a list

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.

 

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.

% 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.

/*append(l1,l2,l3).*/
mem(X,[X|_]).
mem(X,[_|T]):- mem(X,T).

/* insert  a number in the list. */ 
 insert(L,[X|Y],[L|_]).
 insert(L,P,[X|Y],[X|M]):-
 P>1,
 P1 is P-1,
 insert(L,P1,Y,M).
 insert(L,1,[X|Y],M):- append([L],[X|Y],M).

% Output
Prolog Program to insert element in the list. 

4. Write a Prolog program to implement append for two lists.

 

Write a Prolog program to implement append for two lists.

% Write a Prolog program to implement append for two lists.


/*concatenate*/
conc([],L,L).
conc([X|M],N,[X|Q]):-
 conc(M,N,Q). 

% Output
                      Prolog program to implement append for two lists

3. Write a Prolog program to calculate the sum of two numbers.

 

% Write a prolog program to calculate the sum of two numbers.

%  So, what is the function for above mentioned problem.
sum(X,Y):-
 S is X+Y,
 write(S).

% Output
                             Prolog program to calculate the sum of two numbers

2. Write a Prolog program to find the maximum of two numbers.

 

% Write a prolog program to find the maximum of two numbers.

max(X,Y):-
(  
 X=Y -> 
  write('both are equal')
 ;
 X>Y -> 
  (
  Z is X, 
  write(Z)
  )
  ;
  (
  Z is Y, 
  write(Z)
  ) 
).

% Output
Prolog Program to find maximum of two numbers.