The weekly challenge 395 - Task 1: Complex Number

 1 #!/usr/bin/env perl
 2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-395/#TASK1
 3 #
 4 # Task 1: Complex Number
 5 # ======================
 6 #
 7 # You are given two complex numbers as string.
 8 #
 9 # Write a script to return the multiplication of the given complex numbers.
10 #
11 ## Using the formula: (a + bi) x (c + di) = (ac - bd) + (ad + bc)i
12 #
13 ## Example 1
14 ##
15 ## Input: $num1 = "1+1i", $num2 = "1+1i"
16 ## Output: "0+2i"
17 #
18 ## Example 2
19 ##
20 ## Input: $num1 = "1+(-1)i", $num2 = "1+(-1)i"
21 ## Output: "0+(-2)i"
22 #
23 ## Example 3
24 ##
25 ## Input: $num1 = "0+3i", $num2 = "0+4i"
26 ## Output: "-12+0i"
27 #
28 ## Example 4
29 ##
30 ## Input: $num1 = "3+4i", $num2 = "3+(-4)i"
31 ## Output: "25+0i"
32 #
33 ## Example 5
34 ##
35 ## Input: $num1 = "50+(-20)i", $num2 = "-10+30i"
36 ## Output: "100+1700i"
37 #
38 ############################################################
39 ##
40 ## discussion
41 ##
42 ############################################################
43 #
44 # This is straight forward: parse the number strings, calculate the
45 # product, return it as a string.
46 
47 use v5.36;
48 
49 sub complex_number($num1, $num2) {
50     say "Input: \"$num1\", \"$num2\"";
51     my ($a_, $b_) = parse_num($num1);
52     my ($c, $d) = parse_num($num2);
53     my $real = $a_ * $c - $b_ * $d;
54     my $imaginary = $a_ * $d + $b_ * $c;
55     if($imaginary < 0) {
56         $imaginary = "($imaginary)";
57     }
58     say "Output: \"$real+${imaginary}i";
59 }
60 
61 sub parse_num($num) {
62     my ($real, $imaginary);
63     $num =~ s/^(-?[\d.]+)\+//;
64     $real = $1;
65     $num =~ s/i$//;
66     $num =~ s/\(//;
67     $num =~ s/\)//;
68     $imaginary = $num;
69     return ($real, $imaginary);
70 }
71 
72 complex_number("1+1i", "1+1i");
73 complex_number("1+(-1)i", "1+(-1)i");
74 complex_number("0+3i", "0+4i");
75 complex_number("3+4i", "3+(-4)i");
76 complex_number("50+(-20)i", "-10+30i");