From bc0c7033bf770fcb08dc4e0a060832bc63b81e51 Mon Sep 17 00:00:00 2001
From: Arne Sommer <arne@bbop.org>
Date: Sun, 2 Nov 2025 00:05:58 +0100
Subject: week 345 Arne Sommer

---
 challenge-345/arne-sommer/blog.txt            |  1 +
 challenge-345/arne-sommer/raku/ch-1.raku      | 27 +++++++++++++++++++
 challenge-345/arne-sommer/raku/ch-2.raku      | 37 +++++++++++++++++++++++++++
 challenge-345/arne-sommer/raku/last-visitor   | 37 +++++++++++++++++++++++++++
 challenge-345/arne-sommer/raku/peak-positions | 27 +++++++++++++++++++
 5 files changed, 129 insertions(+)
 create mode 100644 challenge-345/arne-sommer/blog.txt
 create mode 100755 challenge-345/arne-sommer/raku/ch-1.raku
 create mode 100755 challenge-345/arne-sommer/raku/ch-2.raku
 create mode 100755 challenge-345/arne-sommer/raku/last-visitor
 create mode 100755 challenge-345/arne-sommer/raku/peak-positions

diff --git a/challenge-345/arne-sommer/blog.txt b/challenge-345/arne-sommer/blog.txt
new file mode 100644
index 0000000000..a544302c19
--- /dev/null
+++ b/challenge-345/arne-sommer/blog.txt
@@ -0,0 +1 @@
+https://raku-musings.com/last-peak.html
\ No newline at end of file
diff --git a/challenge-345/arne-sommer/raku/ch-1.raku b/challenge-345/arne-sommer/raku/ch-1.raku
new file mode 100755
index 0000000000..3db88e2db9
--- /dev/null
+++ b/challenge-345/arne-sommer/raku/ch-1.raku
@@ -0,0 +1,27 @@
+#! /usr/bin/env raku
+
+unit sub MAIN (*@ints where @ints.elems > 0 && all(@ints) ~~ Int,
+		:s(:$strictly),
+		:v(:$verbose));
+
+my $i-offset = 0;
+
+unless $strictly
+{
+  @ints.unshift: -Inf;
+  @ints.push: -Inf;
+  $i-offset = -1;
+}
+
+my @indices;
+
+for 1 .. @ints.end - 1 -> $i
+{
+  my $peak = @ints[$i -1] < @ints[$i] > @ints[$i +1];
+
+  say ": index { $i + $i-offset } (@ints[$i -1] < @ints[$i] > @ints[$i +1]) : $peak" if $verbose;
+
+  @indices.push($i + $i-offset) if $peak;
+}
+
+say "({ @indices.join(",") })";
\ No newline at end of file
diff --git a/challenge-345/arne-sommer/raku/ch-2.raku b/challenge-345/arne-sommer/raku/ch-2.raku
new file mode 100755
index 0000000000..6d5ce46e3b
--- /dev/null
+++ b/challenge-345/arne-sommer/raku/ch-2.raku
@@ -0,0 +1,37 @@
+#! /usr/bin/env raku
+
+unit sub MAIN (*@ints where @ints.elems > 0 && all(@ints) ~~ Int,
+		:v(:$verbose));
+
+my @seen;
+my @ans;
+
+my $x = 0;
+
+for @ints -> $int
+{
+  if $int > 0
+  {
+    $x = 0;
+    @seen.unshift: $int;
+  }
+  elsif $int == -1
+  {
+    if $x < @seen.elems
+    {
+      @ans.push: @seen[$x];
+    }
+    else
+    {
+      @ans.push: -1;
+    }
+    $x++;
+  }
+  else
+  {
+    die "Illegal value $int (legal values: -1,1,2,3,..)";
+  }
+  say ": $int -> seen: { @seen.join(",") } ans: { @ans.join(",") }" if $verbose;
+}
+
+say "({ @ans.join(",") })";
\ No newline at end of file
diff --git a/challenge-345/arne-sommer/raku/last-visitor b/challenge-345/arne-sommer/raku/last-visitor
new file mode 100755
index 0000000000..6d5ce46e3b
--- /dev/null
+++ b/challenge-345/arne-sommer/raku/last-visitor
@@ -0,0 +1,37 @@
+#! /usr/bin/env raku
+
+unit sub MAIN (*@ints where @ints.elems > 0 && all(@ints) ~~ Int,
+		:v(:$verbose));
+
+my @seen;
+my @ans;
+
+my $x = 0;
+
+for @ints -> $int
+{
+  if $int > 0
+  {
+    $x = 0;
+    @seen.unshift: $int;
+  }
+  elsif $int == -1
+  {
+    if $x < @seen.elems
+    {
+      @ans.push: @seen[$x];
+    }
+    else
+    {
+      @ans.push: -1;
+    }
+    $x++;
+  }
+  else
+  {
+    die "Illegal value $int (legal values: -1,1,2,3,..)";
+  }
+  say ": $int -> seen: { @seen.join(",") } ans: { @ans.join(",") }" if $verbose;
+}
+
+say "({ @ans.join(",") })";
\ No newline at end of file
diff --git a/challenge-345/arne-sommer/raku/peak-positions b/challenge-345/arne-sommer/raku/peak-positions
new file mode 100755
index 0000000000..3db88e2db9
--- /dev/null
+++ b/challenge-345/arne-sommer/raku/peak-positions
@@ -0,0 +1,27 @@
+#! /usr/bin/env raku
+
+unit sub MAIN (*@ints where @ints.elems > 0 && all(@ints) ~~ Int,
+		:s(:$strictly),
+		:v(:$verbose));
+
+my $i-offset = 0;
+
+unless $strictly
+{
+  @ints.unshift: -Inf;
+  @ints.push: -Inf;
+  $i-offset = -1;
+}
+
+my @indices;
+
+for 1 .. @ints.end - 1 -> $i
+{
+  my $peak = @ints[$i -1] < @ints[$i] > @ints[$i +1];
+
+  say ": index { $i + $i-offset } (@ints[$i -1] < @ints[$i] > @ints[$i +1]) : $peak" if $verbose;
+
+  @indices.push($i + $i-offset) if $peak;
+}
+
+say "({ @indices.join(",") })";
\ No newline at end of file
-- 
cgit