4 files changed, 126 insertions, 0 deletions
diff --git a/challenge-098/dave-jacoby/blog.txt b/challenge-098/dave-jacoby/blog.txt
new file mode 100644
index 0000000000..832237b620
--- /dev/null
+++ b/challenge-098/dave-jacoby/blog.txt
@@ -0,0 +1 @@
+https://jacoby.github.io/2021/02/01/various-positions-perl-weekly-challenge-98.html
diff --git a/challenge-098/dave-jacoby/perl/ch-1a.pl b/challenge-098/dave-jacoby/perl/ch-1a.pl
new file mode 100644
index 0000000000..28cb0eca12
--- /dev/null
+++ b/challenge-098/dave-jacoby/perl/ch-1a.pl
@@ -0,0 +1,49 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature qw{ say signatures state };
+no warnings qw{ experimental };
+
+use List::Util qw{ sum0 };
+
+use JSON;
+my $json = JSON->new->pretty->canonical;
+
+my $n      = 4;
+my $flag   = 0;
+my @inputs = qw{ twinkie input1.txt input2.txt };
+while ( $flag < @inputs ) {
+    state $flags;
+    for my $input (@inputs) {
+        my $output = readN( $input, $n );
+        do {
+            $flags->{$input} = 1;
+            $flag = sum0 values %$flags;
+            next;
+        } if $output eq '';
+        say qq{\t'$input'\t$n\t'$output'};
+    }
+}
+
+# returns empty string on failure cases, which include
+#   * no file
+#   * index beyond file length
+
+sub readN ( $file, $chars ) {
+    state $index;
+    $index->{$file} //= 0;
+    my $i = $index->{$file};
+    return '' unless -f $file;
+    return '' unless -r $file;
+    return '' if $i > -s $file;
+    my $output = '';
+
+    if ( open my $fh, '<', $file ) {
+        my $string = join '', <$fh>;
+        $output = substr $string, $i, $chars;
+        close $fh;
+    }
+    $index->{$file} += $chars;
+    return $output;
+}
diff --git a/challenge-098/dave-jacoby/perl/ch-1b.pl b/challenge-098/dave-jacoby/perl/ch-1b.pl
new file mode 100644
index 0000000000..fb06d584c4
--- /dev/null
+++ b/challenge-098/dave-jacoby/perl/ch-1b.pl
@@ -0,0 +1,45 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature qw{ say signatures state };
+no warnings qw{ experimental };
+
+use List::Util qw{ sum0 };
+
+use JSON;
+my $json = JSON->new->pretty->canonical;
+
+my $n      = 4;
+my $flag   = 0;
+my @inputs = qw{ twinkie input1.txt input2.txt };
+while ( $flag < @inputs ) {
+    state $flags;
+    for my $input (@inputs) {
+        my $output = readN( $input, $n );
+        do {
+            $flags->{$input} = 1;
+            $flag = sum0 values %$flags;
+            next;
+        } if $output eq '';
+        say qq{\t'$input'\t$n\t'$output'};
+    }
+}
+exit;
+
+# returns empty string on failure cases, which include
+#   * no file
+#   * index beyond file length
+
+sub readN ( $file, $chars ) {
+    state $fhs;
+    return '' unless -f $file;
+    return '' unless -r $file;
+    unless ( $fhs->{$file} ) { open $fhs->{$file}, '<', $file }
+
+    my $fh = $fhs->{$file};
+    my $output ;
+    read $fh, $output, $chars;
+    return $output;
+}
+
diff --git a/challenge-098/dave-jacoby/perl/ch-2.pl b/challenge-098/dave-jacoby/perl/ch-2.pl
new file mode 100644
index 0000000000..3a15e3b280
--- /dev/null
+++ b/challenge-098/dave-jacoby/perl/ch-2.pl
@@ -0,0 +1,31 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature qw{ say signatures state };
+no warnings qw{ experimental };
+
+my @ns;
+push @ns, [ 3,  [ 1,  2,  3,  4 ] ];
+push @ns, [ 6,  [ 1,  3,  5,  7 ] ];
+push @ns, [ 10, [ 12, 15, 16, 18 ] ];
+push @ns, [ 19, [ 11, 13, 15, 17 ] ];
+
+for my $m (@ns) {
+    my $n = $m->[0];
+    my @n = $m->[1]->@*;
+    my $i = search_insert_position( $n, @n );
+    say qq{Input:  \$n = $n};
+    say qq{        \@n = } . join ', ', @n;
+    say qq{Output: \$i = $i};
+    say '';
+}
+
+sub search_insert_position ( $n, @n ) {
+    my $i = 0;
+    while ( $i < @n ) {
+        return $i if $n <= $n[$i];
+        $i++;
+    }
+    return $i;
+}