RabbitFarm

The examples used here are from the weekly challenge problem statement and demonstrate the working solution.

Part 1: Acronyms

You are given an array of words and a word. Write a script to return true if concatenating the first letter of each word in the given array matches the given word, return false otherwise.

We can do this in a single predicate which uses maplist to get the first character from each word, which we’ll take as a list of character code lists.

The rest of the code just wraps this single predicate into a file.

Sample Run

$ gprolog --consult-file prolog/ch-1.p 
| ?- acronym(["Perl", "Weekly", "Challenge"], "PWC"). 
 
yes 
| ?- acronym(["Bob", "Charlie", "Joe"], "BCJ"). 
 
yes 
| ?- acronym(["Morning", "Good"], "MM"). 
 
no 
| ?-
    

Part 2: Friendly Strings

You are given two strings. Write a script to return true if swapping any two letters in one string match the other string, return false otherwise.

This is going to be a quick one. First we will check that we can subtract/3 the two words (character code lists) and obtain an empty list. Then we’ll check in which places the words differ. They must only differ in exactly two places.

Finally, let’s assemble our completed code into a single file.

Sample Run

$ gprolog --consult-file prolog/ch-2.p 
| ?- friendly("desc", "dsec"). 
 
yes 
| ?- friendly("cat", "dog"). 
 
no 
| ?- friendly("stripe", "sprite"). 
 
yes 
| ?-
    

References

The Weekly Challenge 317
Generated Code