Challenge 73

2 files changed, 77 insertions, 0 deletions

diff --git a/challenge-073/dave-jacoby/perl/ch-1.pl b/challenge-073/dave-jacoby/perl/ch-1.pl
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+++ b/challenge-073/dave-jacoby/perl/ch-1.pl
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+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature qw{ say signatures state };
+no warnings qw{ experimental };
+
+use List::Util qw{ min };
+
+# You are given an array of integers @A and sliding window size $S.
+
+# Write a script to create an array of min from each sliding window.
+
+# Example
+# Input: @A = (1, 5, 0, 2, 9, 3, 7, 6, 4, 8) and $S = 3
+# Output: (0, 0, 0, 2, 3, 3, 4, 4)
+
+# [(1 5 0) 2 9 3 7 6 4 8] = Min (0)
+# [1 (5 0 2) 9 3 7 6 4 8] = Min (0)
+# [1 5 (0 2 9) 3 7 6 4 8] = Min (0)
+# [1 5 0 (2 9 3) 7 6 4 8] = Min (2)
+# [1 5 0 2 (9 3 7) 6 4 8] = Min (3)
+# [1 5 0 2 9 (3 7 6) 4 8] = Min (3)
+# [1 5 0 2 9 3 (7 6 4) 8] = Min (4)
+# [1 5 0 2 9 3 7 (6 4 8)] = Min (4)
+
+my @array = ( 1, 5, 0, 2, 9, 3, 7, 6, 4, 8 );
+my $s = 3;
+
+sliding_window( $s, \@array );
+
+sub sliding_window ( $s, $arr ) {
+    my @arr   = $arr->@*;
+    my $max_n = $#arr;
+
+    for my $n ( 0 .. $#arr ) {
+        next if $n + 2 > $max_n;
+        my $min = min map { $arr[$_] } $n .. $n + 2;
+
+        print '[';
+        for my $i ( 0 .. $#arr ) {
+            print $i == $n ? '(' : ' ';
+            print $arr[$i];
+            print $i == $n +2 ? ')' : ' ';
+        }
+        say qq{] = Min ($min)};
+    }
+}
+
diff --git a/challenge-073/dave-jacoby/perl/ch-2.pl b/challenge-073/dave-jacoby/perl/ch-2.pl
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+++ b/challenge-073/dave-jacoby/perl/ch-2.pl
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+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature qw{ say signatures state };
+no warnings qw{ experimental };
+
+use List::Util qw{min};
+
+smallest_neighbour( 7, 8, 3, 12, 10 );
+smallest_neighbour( 4, 6, 5 );
+smallest_neighbour( map { 1 + int rand 15 } 0 .. 2 + int rand 10 );
+
+sub smallest_neighbour ( @array ) {
+    my @output;
+    my @left;
+
+    say join "\t", 'INPUT:  ', join ', ', @array;
+    while (@array) {
+        my $k = shift @array;
+        my $l = min grep { $_ < $k } @left;
+        push @output, defined $l ? $l : 0;
+        push @left, $k;
+    }
+
+    say join "\t", 'OUTPUT: ', join ', ', @output;
+    say '';
+}