harshsulakhe / cs-f214-a1

Assignment 1 for CS F214 at BITS Pilani.

Logic in Computer Science (CS F214)

Assignment-1 (Fall Semester '19)

Problem 1: Given a weighted undirected graph G = (V, E). The weight on an edge (v1, v2) represents the distance between the vertices v1 and v2 {vi V; and (vi, vj) E}. Given a set of weights of edges in the form of prolog clauses:

weight(p, q, 20).
weight(q, r, 5).

Write a prolog program to check if there exists a path between two given vertices. Print the path and its length, if it exists. For example: ?- findPath(p, r, Path, L). the prolog interpreter should print

Path = [p, q, r]
L = 25

Note that the user should print an alternative path if it exists on each press of a semi colon and print no if no path exists. Your program should avoid traversing through cycles, if any.

Problem 2: Write a Prolog predicate for each of the following operations on a list:

• sublist(X,Y): true if list X is a sublist of list Y. A sublist is the original list, in the same order, but with no/some elements removed.
• has_triplicate(X): true if list X contains at least three copies of an element. It also prints the element which is triplicated.
• remove_nth(N,X,Y): prints list Y which is the list X with its Nth element removed. If X does not have an Nth element then the predicate should fail. Assume that N > 0.
• remove_every_other(X,Y): prints a list Y which is the list X with every other element removed (the two lists should have the same first element).

Note: Each predicate should be able to print the alternative solutions if they exist.

Contributors:

• Shreyans Jain (2018A7PS0253P)
• Aryaman Bhagat (2018A7PS0248P)
• Pranav Gupta (2018A7PS0190P)
• Harsh Sulakhe (2018A7PS0186P)