The weekly challenge 307 - Task 1: Check Order

 1 #!/usr/bin/env perl
 2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-307/#TASK1
 3 #
 4 # Task 1: Check Order
 5 # ===================
 6 #
 7 # You are given an array of integers, @ints.
 8 #
 9 # Write a script to re-arrange the given array in an increasing order and
10 # return the indices where it differs from the original array.
11 #
12 ## Example 1
13 ##
14 ## Input: @ints = (5, 2, 4, 3, 1)
15 ## Output: (0, 2, 3, 4)
16 ##
17 ## Before: (5, 2, 4, 3, 1)
18 ## After : (1, 2, 3, 4, 5)
19 ##
20 ## Difference at indices: (0, 2, 3, 4)
21 #
22 ## Example 2
23 ##
24 ## Input: @ints = (1, 2, 1, 1, 3)
25 ## Output: (1, 3)
26 ##
27 ## Before: (1, 2, 1, 1, 3)
28 ## After : (1, 1, 1, 2, 3)
29 ##
30 ## Difference at indices: (1, 3)
31 #
32 ## Example 3
33 ##
34 ## Input: @ints = (3, 1, 3, 2, 3)
35 ## Output: (0, 1, 3)
36 ##
37 ## Before: (3, 1, 3, 2, 3)
38 ## After : (1, 2, 3, 3, 3)
39 ##
40 ## Difference at indices: (0, 1, 3)
41 #
42 ############################################################
43 ##
44 ## discussion
45 ##
46 ############################################################
47 #
48 # Create the sorted array, then comapre the two arrays by index.
49 # Remember all positions where the two arrays differ.
50 
51 use v5.36;
52 
53 check_order(5, 2, 4, 3, 1);
54 check_order(1, 2, 1, 1, 3);
55 check_order(3, 1, 3, 2, 3);
56 
57 sub check_order {
58    my @ints = @_;
59    say "Input: (" . join(", ", @ints) . ")";
60    my @sorted = sort {$a<=>$b} @ints;
61    my @result = ();
62    foreach my $i (0..$#ints) {
63       push @result, $i if $ints[$i] != $sorted[$i];
64    }
65    say "Output: (" . join(", ", @result) . ")";
66 }