The weekly challenge 358 - Task 2: Encrypted String

 1 #!/usr/bin/env perl
 2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-358/#TASK2
 3 #
 4 # Task 2: Encrypted String
 5 # ========================
 6 #
 7 # You are given a string $str and an integer $int.
 8 #
 9 # Write a script to encrypt the string using the algorithm - for each character
10 # $char in $str, replace $char with the $int th character after $char in the
11 # alphabet, wrapping if needed and return the encrypted string.
12 #
13 ## Example 1
14 ##
15 ## Input: $str = "abc", $int = 1
16 ## Output: "bcd"
17 #
18 #
19 ## Example 2
20 ##
21 ## Input: $str = "xyz", $int = 2
22 ## Output: "zab"
23 #
24 #
25 ## Example 3
26 ##
27 ## Input: $str = "abc", $int = 27
28 ## Output: "bcd"
29 #
30 #
31 ## Example 4
32 ##
33 ## Input: $str = "hello", $int = 5
34 ## Output: "mjqqt"
35 #
36 #
37 ## Example 5
38 ##
39 ## Input: $str = "perl", $int = 26
40 ## Output: "perl"
41 #
42 ############################################################
43 ##
44 ## discussion
45 ##
46 ############################################################
47 #
48 # We simply use the tr/// operator, and prepare the left and
49 # right side of that operation in two strings. That's why we
50 # need to eval the tr operation.
51 
52 use v5.36;
53 
54 encrypted_string("abc", 1);
55 encrypted_string("xyz", 2);
56 encrypted_string("abc", 27);
57 encrypted_string("hello", 5);
58 encrypted_string("perl", 26);
59 
60 sub encrypted_string($str, $int) {
61     say "Input: \"$str\", $int";
62     $int = $int % 26;
63     my $chars = "abcdefghijklmnopqrstuvwxyz";
64     my $replacement = substr($chars, $int) . substr($chars, 0, $int);
65     $replacement = $chars unless $int;
66     $_ = $str;
67     eval "tr/$chars/$replacement/";
68     say "Output: $_";
69 }