PROLOG-Assignment 2 List Processing Problems and Cut Solved

Write PROLOG programs:  

1.  To add an element to a list provided it is not present in the list.

2.  To delete first occurrence of an element from a list.  

3.  To delete all occurrences of an element from a list.  

4.  To replace the first occurrence of an element X in L with Y giving the result in L1.

5.  has_duplicate(L), that determines whether list L has duplicate elements.  

6.  To duplicate the elements of a list. Example:

?- duplicate([a,b,c,c,d],X).

{X = [a,a,b,b,c,c,c,c,d,d]}

7, To duplicate the elements of a list a given number of times.

Example:

?- duplicate2([a,b,c],3,X).

{X = [a,a,a,b,b,b,c,c,c]}

 

What are the results of the goal:

?- duplicate2(X,3,Y).

 

8.     To determine whether a list is a sub list of another list. A list is a sub list of another list if it’s elements are present in another list consecutively and in the same order.

9.     To determine whether a set is a subset of another set.  

10.  To determine intersection of two sets.  

12.To determine union of two sets.  

13.To determine difference of two sets.

 14.To determine symmetric difference of two sets.  

15.  To replace n th element by another element X in L, leaving the resultant list in L1.

16.  to remove every N'th element from a list. Example:

?- remove([a,b,c,d,e,f,g,h,i,k],3,X).

{X = [a,b,d,e,g,h,k]}

 

 For the problems 17 – 18 assume L1, L2 and L denote lists of terms.  

17.  Interleave alternate elements of L1 and L2 into L. For example, if L1= [a, b, c] and L2= [1, 2], then L= [a, 1, b, 2, c].  

18.Transpose L1, L2 into L. That is, if L1= [a, b, c] and L2= [1, 2, 3], then L= [(a, 1), (b, 2), (c, 3)].  

19.  To split a list into two parts; the length of the first part is given. Do not use any predefined predicates.

 

Example:

?- split([a,b,c,d,e,f,g,h,i,k],3,L1,L2).

{L1 = [a,b,c], L2 = [d,e,f,g,h,i,k]}

 

20.  To extract a slice from a list.

Given two indices, I and K, the slice is the list containing the elements between the I'th and K'th element of the original list (both limits included). Start counting the elements with 1.

 

Example:

?- slice([a,b,c,d,e,f,g,h,i,k],3,7,L).

{X = [c,d,e,f,g]}

 

21.  To insert an element at a given position into a list.

Example:

?- insert_at(alfa,[a,b,c,d],2,L).

{L = [a,alfa,b,c,d]}

  

For the problems 22 - 30 assume L and L1 is a list of terms.  

22.  To remove_every_other (L, L1). List L1 is just list L with every other element removed (the two lists should have the same first element).  

23.  cutlast (L, L1) that defines L1 to be obtained from L with last element removed.  

24.  trim (N, L, L1) that defines L1 to be obtained from L with first N elements removed.  

25.trimlast (N, L, L1) that defines L1 to be obtained from L with last N elements removed.  

26.exchange_first_last(L, L1), defines that L1 to be obtained from L with first and last elements exchanged.  

Example:

 ?-exchange_first_last([a, b, c, d, e], X).  

{X= [e, b, c, d, a]}  

27 circular_left_shift(L, L1). That is, if L= [a, b, c, d, e, f] then L1= [b, c, d, e, f, a]..  

28. circular_right_shift(L, L1). That is, if L= [a, b, c, d, e, f] then L1= [f, a, b, c, d, e]

 [Try using circular_left_shift in 27 to implement circular_right_shift.]  

29.To delete the middle element from an odd-numbered list L into a list L1.  

30.To delete two middle elements from an even-numbered list L into a list L1.