The weekly challenge 393 - Task 1: Pythagoras Multiplied

 1 #!/usr/bin/env perl
 2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-393/#TASK1
 3 #
 4 # Task 1: Pythagoras Multiplied
 5 # =============================
 6 #
 7 # You are given a positive integer n.
 8 #
 9 # Find the number of all positive integer triplets (a, b, c) so that a^2 + b^2
10 # = c^2 and a, b and c are integers <= n.
11 #
12 ## Example 1
13 ##
14 ## Input: $n = 20
15 ## Output: 12
16 ##
17 ## (3,4,5),  (4,3,5),   (5,12,13),(6,8,10),
18 ## (8,6,10), (8,15,17), (9,12,15),(12,5,13),
19 ## (12,9,15),(12,16,20),(15,8,17),(16,12,20)
20 #
21 ## Example 2
22 ##
23 ## Input: $n = 7
24 ## Output: 2
25 ##
26 ## (3,4,5),(4,3,5)
27 #
28 ## Example 3
29 ##
30 ## Input: $n = 1
31 ## Output: 0
32 #
33 ## Example 4
34 ##
35 ## Input: $n = 15
36 ## Output: 8
37 #
38 ## Example 5
39 ##
40 ## Input: $n = 30
41 ## Output: 22
42 #
43 ############################################################
44 ##
45 ## discussion
46 ##
47 ############################################################
48 #
49 # We simply create all possible combinations for a, b and c and count
50 # the ones where a^2 + b^2 == c^2.
51 
52 use v5.36;
53 
54 
55 pythagorasmultiplied(20);
56 pythagorasmultiplied(7);
57 pythagorasmultiplied(1);
58 pythagorasmultiplied(15);
59 pythagorasmultiplied(30);
60 
61 sub pythagorasmultiplied($n) {
62     say "Input: $n";
63     my $count = 0;
64     foreach my $i (1..$n) {
65         foreach my $j (1..$n) {
66             foreach my $k (1..$n) {
67                 if($i*$i + $j*$j == $k*$k) {
68                     $count++;
69                 }
70             }
71         }
72     }
73     say "Output: $count";
74 }
75