The weekly challenge 375 - Task 2: Find K-Beauty

 1 #!/usr/bin/env perl
 2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-375/#TASK2
 3 #
 4 # Task 2: Find K-Beauty
 5 # =====================
 6 #
 7 # You are given a number and a digit (k).
 8 #
 9 # Write a script to find the K-Beauty of the given number. The K-Beauty of an
10 # integer number is defined as the number of substrings of given number when it
11 # is read as a string has length of ‘k’ and is a divisor of given number.
12 #
13 ## Example 1
14 ##
15 ## Input: $num = 240, $k = 2
16 ## Output: 2
17 ##
18 ## Substring with length 2:
19 ## 24: 240 is divisible by 24
20 ## 40: 240 is divisible by 40
21 #
22 ## Example 2
23 ##
24 ## Input: $num = 1020, $k = 2
25 ## Output: 3
26 ##
27 ## Substring with length 2:
28 ## 10: 240 is divisible by 10
29 ## 02: 240 is divisible by 2
30 ## 20: 240 is divisible by 20
31 #
32 ## Example 3
33 ##
34 ## Input: $num = 444, $k = 2
35 ## Output: 0
36 ##
37 ## Substring with length 2:
38 ## First "44": 444 is not divisible by 44
39 ## Second "44": 444 is not divisible by 44
40 #
41 ## Example 4
42 ##
43 ## Input: $num = 17, $k = 2
44 ## Output: 1
45 ##
46 ## Substring with length 2:
47 ## 17: 17 is divisible by 17
48 #
49 ## Example 5
50 ##
51 ## Input: $num = 123, $k = 1
52 ## Output: 2
53 ##
54 ## Substring with length 1:
55 ## 1: 123 is divisible by 1
56 ## 2: 123 is not divisible by 2
57 ## 3: 123 is divisible by 3
58 #
59 ############################################################
60 ##
61 ## discussion
62 ##
63 ############################################################
64 #
65 # We just create all substrings of length k and count them if $num
66 # is divisible by that number.
67 
68 use v5.36;
69 
70 find_k_beauty(240, 2);
71 find_k_beauty(1020, 2);
72 find_k_beauty(444, 2);
73 find_k_beauty(17, 2);
74 find_k_beauty(123, 1);
75 
76 sub find_k_beauty($num, $k) {
77     say "Input: num = $num, k = $k";
78     my $n = $num;
79     my $k_beauty = 0;
80     while(length($n) >= $k) {
81         my $s = substr($n, 0, $k);
82         $s =~ s/^0*//;
83         $n = substr($n, 1);
84         $k_beauty++ unless $num % $s;
85     }
86     say "Output: $k_beauty";
87 }