The weekly challenge 319 - Task 2: Minimum Common

 1 #!/usr/bin/env perl
 2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-319/#TASK2
 3 #
 4 # Task 2: Minimum Common
 5 # ======================
 6 #
 7 # You are given two arrays of integers.
 8 #
 9 # Write a script to return the minimum integer common to both arrays. If none
10 # found return -1.
11 #
12 ## Example 1
13 ##
14 ## Input: @array_1 = (1, 2, 3, 4)
15 ##        @array_2 = (3, 4, 5, 6)
16 ## Output: 3
17 ##
18 ## The common integer in both arrays: 3, 4
19 ## The minimum is 3.
20 #
21 #
22 ## Example 2
23 ##
24 ## Input: @array_1 = (1, 2, 3)
25 ##        @array_2 = (2, 4)
26 ## Output: 2
27 #
28 #
29 ## Example 3
30 ##
31 ## Input: @array_1 = (1, 2, 3, 4)
32 ##        @array_2 = (5, 6, 7, 8)
33 ## Output: -1
34 #
35 ############################################################
36 ##
37 ## discussion
38 ##
39 ############################################################
40 #
41 # We turn the elements from the first array into the keys of a hash.
42 # Then we walk the sorted second list. As soon as an element can be
43 # found in the hash, it is the searched minimum. If we didn't find
44 # any element, we just return the default for our result, -1.
45 
46 use v5.36;
47 
48 minimum_common( [1, 2, 3, 4], [3, 4, 5, 6] );
49 minimum_common( [1, 2, 3], [2, 4] );
50 minimum_common( [1, 2, 3, 4],[5, 6, 7, 8] );
51 
52 sub minimum_common( $array_1, $array_2 ) {
53     say "Input: (" . join(", ", @$array_1) . "),";
54     say "       (" . join(", ", @$array_2) . ")";
55     my $tmp;
56     my $result = -1;
57     foreach my $elem (@$array_1) {
58         $tmp->{$elem} = 1;
59     }
60     foreach my $elem (sort {$a <=> $b} @$array_2) {
61         if($tmp->{$elem}) {
62             $result = $elem;
63             last;
64         }
65     }
66     say "Output: $result";
67 }