The weekly challenge 331 - Task 2: Buddy Strings

 1 #!/usr/bin/env perl
 2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-331/#TASK2
 3 #
 4 # Task 2: Buddy Strings
 5 # =====================
 6 #
 7 # You are given two strings, source and target.
 8 #
 9 # Write a script to find out if the given strings are Buddy Strings.
10 #
11 ## If swapping of a letter in one string make them same as the other then they
12 ## are `Buddy Strings`.
13 #
14 #
15 ## Example 1
16 ##
17 ## Input: $source = "fuck"
18 ##        $target = "fcuk"
19 ## Output: true
20 ##
21 ## The swapping of 'u' with 'c' makes it buddy strings.
22 #
23 #
24 ## Example 2
25 ##
26 ## Input: $source = "love"
27 ##        $target = "love"
28 ## Output: false
29 #
30 #
31 ## Example 3
32 ##
33 ## Input: $source = "fodo"
34 ##        $target = "food"
35 ## Output: true
36 #
37 #
38 ## Example 4
39 ##
40 ## Input: $source = "feed"
41 ##        $target = "feed"
42 ## Output: true
43 #
44 ############################################################
45 ##
46 ## discussion
47 ##
48 ############################################################
49 #
50 # We split one of the words (let's decide for the target, but
51 # we could equally use the source here) into individual characters.
52 # Then we just try to swap each character against each other, and if
53 # the resulting string matches the source, we return true. Then we
54 # swap back of course, jumping to the next pair of characters to
55 # swap. If we didn't find a true solution at the end, we can
56 # return false.
57 
58 use v5.36;
59 
60 buddy_strings("fuck", "fcuk");
61 buddy_strings("love", "love");
62 buddy_strings("fodo", "food");
63 buddy_strings("feed", "feed");
64 
65 sub buddy_strings($source, $target) {
66     say "Input: \"$source\", \"$target\"";
67     my @t_chars = split //, $target;
68     foreach my $i (0..$#t_chars) {
69         foreach my $j ($i+1..$#t_chars) {
70             ($t_chars[$i], $t_chars[$j]) = ($t_chars[$j], $t_chars[$i]);
71             my $tmp = join("", @t_chars);
72             if($source eq $tmp) {
73                 return say "Output: true";
74             }
75             ($t_chars[$i], $t_chars[$j]) = ($t_chars[$j], $t_chars[$i]);
76         }
77     }
78     say "Output: false";
79 }