The weekly challenge 376 - Task 1: Chessboard Squares

 1 #!/usr/bin/env perl
 2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-376/#TASK1
 3 #
 4 # Task 1: Chessboard Squares
 5 # ==========================
 6 #
 7 # You are given two coordinates of a square on 8x8 chessboard.
 8 #
 9 # Write a script to find the given two coordinates have the same colour.
10 #
11 # 8 W B W B W B W B
12 # 7 B W B W B W B W
13 # 6 W B W B W B W B
14 # 5 B W B W B W B W
15 # 4 W B W B W B W B
16 # 3 B W B W B W B W
17 # 2 W B W B W B W B
18 # 1 B W B W B W B W
19 #   a b c d e f g h
20 #
21 ## Example 1
22 ##
23 ## Input: $c1 = "a7", $c2 = "f4"
24 ## Output: true
25 #
26 ## Example 2
27 ##
28 ## Input: $c1 = "c1", $c2 = "e8"
29 ## Output: false
30 #
31 ## Example 3
32 ##
33 ## Input: $c1 = "b5", $c2 = "h2"
34 ## Output: false
35 #
36 ## Example 4
37 ##
38 ## Input: $c1 = "f3", $c2 = "h1"
39 ## Output: true
40 #
41 ## Example 5
42 ##
43 ## Input: $c1 = "a1", $c2 = "g8"
44 ## Output: false
45 #
46 ############################################################
47 ##
48 ## discussion
49 ##
50 ############################################################
51 #
52 # We translate a through h to numbers in the range 1 through 8.
53 # Then two coordinates have the same color if the sum of their
54 # coordinates share the same parity.
55 
56 use v5.36;
57 
58 chessboard_squares("a7", "f4");
59 chessboard_squares("c1", "e8");
60 chessboard_squares("b5", "h2");
61 chessboard_squares("f3", "h1");
62 chessboard_squares("a1", "g8");
63 
64 sub chessboard_squares($c1, $c2) {
65     say "Input: c1 = $c1, c2 = $c2";
66     my ($column1, $row1) = split //, $c1;
67     my ($column2, $row2) = split //, $c2;
68     my $column_to_number = {
69         "a" => 1, "b" => 2, "c" => 3, "d" => 4,
70         "e" => 5, "f" => 6, "g" => 7, "h" => 8
71     };
72     if ( ($column_to_number->{$column1} + $row1) % 2
73         == ($column_to_number->{$column2} + $row2) % 2) {
74         say "Output: true";
75     } else {
76         say "Output: false";
77     }
78 }