From da5ece1804223a51722105d1e269fb3d78c863c6 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Mon, 7 Feb 2022 11:44:50 +0100
Subject: Week 151: Tests

---
 challenge-151/abigail/t/ctest.ini      | 9 +++++++++
 challenge-151/abigail/t/input-1-1      | 2 ++
 challenge-151/abigail/t/input-2-1      | 2 ++
 challenge-151/abigail/t/output-1-1.exp | 2 ++
 challenge-151/abigail/t/output-2-1.exp | 2 ++
 5 files changed, 17 insertions(+)
 create mode 100644 challenge-151/abigail/t/ctest.ini
 create mode 100644 challenge-151/abigail/t/input-1-1
 create mode 100644 challenge-151/abigail/t/input-2-1
 create mode 100644 challenge-151/abigail/t/output-1-1.exp
 create mode 100644 challenge-151/abigail/t/output-2-1.exp

diff --git a/challenge-151/abigail/t/ctest.ini b/challenge-151/abigail/t/ctest.ini
new file mode 100644
index 0000000000..0a8cb97d18
--- /dev/null
+++ b/challenge-151/abigail/t/ctest.ini
@@ -0,0 +1,9 @@
+# 
+# Configuration file for running tests, using ctest.
+# See https://github.com/Abigail/Misc/blob/master/ctest
+# 
+
+[names]
+1-1 = Given Examples
+2-1 = Given Examples
+
diff --git a/challenge-151/abigail/t/input-1-1 b/challenge-151/abigail/t/input-1-1
new file mode 100644
index 0000000000..61fb9ed0dc
--- /dev/null
+++ b/challenge-151/abigail/t/input-1-1
@@ -0,0 +1,2 @@
+1 | 2 3 | 4 5
+1 | 2 3 | 4 *  * 5 | * 6
diff --git a/challenge-151/abigail/t/input-2-1 b/challenge-151/abigail/t/input-2-1
new file mode 100644
index 0000000000..14b0f0f2c6
--- /dev/null
+++ b/challenge-151/abigail/t/input-2-1
@@ -0,0 +1,2 @@
+2 4 5
+4 2 3 6 5 3
diff --git a/challenge-151/abigail/t/output-1-1.exp b/challenge-151/abigail/t/output-1-1.exp
new file mode 100644
index 0000000000..4792e70f33
--- /dev/null
+++ b/challenge-151/abigail/t/output-1-1.exp
@@ -0,0 +1,2 @@
+2
+3
diff --git a/challenge-151/abigail/t/output-2-1.exp b/challenge-151/abigail/t/output-2-1.exp
new file mode 100644
index 0000000000..dd80f6a91d
--- /dev/null
+++ b/challenge-151/abigail/t/output-2-1.exp
@@ -0,0 +1,2 @@
+7
+13
-- 
cgit 


From 03fe3f90231fcea43fb5911dc722d9c788cac92d Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Mon, 7 Feb 2022 13:28:46 +0100
Subject: Week 151: Perl solutions

---
 challenge-151/abigail/perl/ch-1.pl | 39 ++++++++++++++++++++++++++++++++++++++
 challenge-151/abigail/perl/ch-2.pl | 37 ++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)
 create mode 100644 challenge-151/abigail/perl/ch-1.pl
 create mode 100644 challenge-151/abigail/perl/ch-2.pl

diff --git a/challenge-151/abigail/perl/ch-1.pl b/challenge-151/abigail/perl/ch-1.pl
new file mode 100644
index 0000000000..73296d77c3
--- /dev/null
+++ b/challenge-151/abigail/perl/ch-1.pl
@@ -0,0 +1,39 @@
+#!/opt/perl/bin/perl
+
+use 5.032;
+
+use strict;
+use warnings;
+no  warnings 'syntax';
+
+use experimental 'signatures';
+use experimental 'lexical_subs';
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+
+#
+# Run as: perl ch-1.pl < input-file
+#
+
+#
+# We'll store the tree in a triangular 2-d array, with
+# the children on node on position [$d, $k] on positions
+# [$d + 1, 2 * $k] and [$d + 1, 2 * $k + 1].
+#
+# Finding the first node without children is trivial.
+#
+TREE: while (<>) {
+    chomp;
+    my @tree = map {[map {$_ ne '*'} /\S+/g]} split /\|/;
+    foreach my $d (keys @tree) {
+        foreach my $i (keys @{$tree [$d]}) {
+            if ($tree [$d] [$i] && !$tree [$d + 1] [2 * $i]
+                                && !$tree [$d + 1] [2 * $i + 1]) {
+                say $d + 1;
+                next TREE;
+            }
+        }
+    }
+}
diff --git a/challenge-151/abigail/perl/ch-2.pl b/challenge-151/abigail/perl/ch-2.pl
new file mode 100644
index 0000000000..263bede352
--- /dev/null
+++ b/challenge-151/abigail/perl/ch-2.pl
@@ -0,0 +1,37 @@
+#!/opt/perl/bin/perl
+
+use 5.032;
+
+use strict;
+use warnings;
+no  warnings 'syntax';
+
+use experimental 'signatures';
+use experimental 'lexical_subs';
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+
+#
+# Run as: perl ch-2.pl < input-file
+#
+
+use List::Util qw [max];
+
+#
+# An algorithm we've seen many times before. For each house, we either
+# rob it, or skip it. And we always have to skip the next house.
+# Skipping more than two houses in succession is never a good idea, but
+# work we'll do extra in the beginning (by skipping more than two house)
+# we get back later on, as we're caching all results.
+#
+sub best;
+sub best ($vals, $i = 0) {
+    state $cache;
+    $i or $cache = [];
+    $$cache [$i] ||= $$vals [$i] + max 0, map {best $vals, $_} $i + 2 .. $#$vals
+}
+
+
+say best [/[0-9]+/g] while <>;
-- 
cgit 


From 1a21a2b719818bb32eaa46d14d91379edc7836ce Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Mon, 7 Feb 2022 14:10:22 +0100
Subject: Week 151: AWK solutions

---
 challenge-151/abigail/awk/ch-1.awk | 42 ++++++++++++++++++++++++++++++++++++++
 challenge-151/abigail/awk/ch-2.awk | 28 +++++++++++++++++++++++++
 2 files changed, 70 insertions(+)
 create mode 100644 challenge-151/abigail/awk/ch-1.awk
 create mode 100644 challenge-151/abigail/awk/ch-2.awk

diff --git a/challenge-151/abigail/awk/ch-1.awk b/challenge-151/abigail/awk/ch-1.awk
new file mode 100644
index 0000000000..314efa9a0a
--- /dev/null
+++ b/challenge-151/abigail/awk/ch-1.awk
@@ -0,0 +1,42 @@
+#!/usr/bin/awk
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+
+#
+# Run as: awk -f ch-1.awk < input-file
+#
+
+{
+    #
+    # Read in tree
+    #
+    delete tree
+    D = 0
+    i = 0
+    for (k = 0; k < NF; k ++) {
+        if ($k == "|") {
+            D ++
+            i = 0
+        }
+        else {
+            tree [D, i ++] = $k == "*" ? 0 : 1
+        }
+    }
+
+    #
+    # Find first node without children
+    #
+    for (d = 0; d <= D; d ++) {
+        for (i = 0; i < 2 ^ d; i ++) {
+            if (tree [d, i] && !tree [d + 1, 2 * i] && 
+                               !tree [d + 1, 2 * i + 1]) {
+                print d + 1
+                next
+            }
+        }
+    }
+}
+
+
diff --git a/challenge-151/abigail/awk/ch-2.awk b/challenge-151/abigail/awk/ch-2.awk
new file mode 100644
index 0000000000..3eb76a8e05
--- /dev/null
+++ b/challenge-151/abigail/awk/ch-2.awk
@@ -0,0 +1,28 @@
+#!/usr/bin/awk
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+
+#
+# Run as: awk -f ch-2.awk < input-file
+#
+
+function best (i, max, sum, k) {
+    if (!(i in cache)) {
+        max = 0
+        for (k = i + 2; k <= NF; k ++) {
+            sum = best(k)
+            if (sum > max) {
+                max = sum
+            }
+        }
+        cache [i] = $i + max
+    }
+    return cache [i]
+}
+
+{
+    delete cache
+    print best(1)
+}
-- 
cgit 


From 98a74265eb245f20dcc038edfca401e67d6cfd4b Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Mon, 7 Feb 2022 18:10:56 +0100
Subject: Week 151: No recursion for part 2

---
 challenge-151/abigail/awk/ch-2.awk | 26 ++++++++++++--------------
 challenge-151/abigail/perl/ch-2.pl | 38 ++++++++++++++++++++++++++++----------
 2 files changed, 40 insertions(+), 24 deletions(-)

diff --git a/challenge-151/abigail/awk/ch-2.awk b/challenge-151/abigail/awk/ch-2.awk
index 3eb76a8e05..73d9b19812 100644
--- a/challenge-151/abigail/awk/ch-2.awk
+++ b/challenge-151/abigail/awk/ch-2.awk
@@ -8,21 +8,19 @@
 # Run as: awk -f ch-2.awk < input-file
 #
 
-function best (i, max, sum, k) {
-    if (!(i in cache)) {
-        max = 0
-        for (k = i + 2; k <= NF; k ++) {
-            sum = best(k)
-            if (sum > max) {
-                max = sum
-            }
-        }
-        cache [i] = $i + max
-    }
-    return cache [i]
+function max (a, b) {
+    return a < b ? b : a
 }
 
 {
-    delete cache
-    print best(1)
+    delete best
+    for (i = NF; i > 0; i --) {
+        best [i] = NF <= 2     ? $i                                     \
+                 : i == NF     ? $i                                     \
+                 : i == 1      ? $i     + best [i + 2]                  \
+                 : i == NF - 1 ? max($i,  best [i + 1])                 \
+                 :               max($i + best [i + 2], best [i + 1])
+    }
+    print best [1]
 }
+
diff --git a/challenge-151/abigail/perl/ch-2.pl b/challenge-151/abigail/perl/ch-2.pl
index 263bede352..5f5519381f 100644
--- a/challenge-151/abigail/perl/ch-2.pl
+++ b/challenge-151/abigail/perl/ch-2.pl
@@ -20,17 +20,35 @@ use experimental 'lexical_subs';
 use List::Util qw [max];
 
 #
-# An algorithm we've seen many times before. For each house, we either
-# rob it, or skip it. And we always have to skip the next house.
-# Skipping more than two houses in succession is never a good idea, but
-# work we'll do extra in the beginning (by skipping more than two house)
-# we get back later on, as we're caching all results.
+# We'll calculate the best way to rob the houses by working backwards.
+# For each house, there are two options: rob the house, or skip it.
+# The maximum value we get for robbing the house is the sum of
+# the value of the current house, plus the maximum we can get
+# if we started two houses down. The maximum value we can get by
+# not robbing this house is the best we can get by starting from
+# the next house.
 #
-sub best;
-sub best ($vals, $i = 0) {
-    state $cache;
-    $i or $cache = [];
-    $$cache [$i] ||= $$vals [$i] + max 0, map {best $vals, $_} $i + 2 .. $#$vals
+# We need some fiddling around the edges:
+#    - Maximizing the value starting from the last house is by robbing it.
+#    - Maximizing the value starting from the penultimate house is
+#      robbing the most valuable of the last two houses.
+#    - If there are only two houses, rob the current house.
+#    - The first house should always be robbed (a requirement); the
+#      maximum value which can be achieved we get by starting from the
+#      third house, adding the value of the first.
+#
+
+sub best ($houses) {
+    my @best;
+    foreach my $i (reverse keys @$houses) {
+        $best [$i] = @$houses < 2        ?     $$houses [$i]
+                   : $i == $#$houses     ?     $$houses [$i]
+                   : $i == 0             ?     $$houses [$i] + $best [$i + 2]
+                   : $i == $#$houses - 1 ? max $$houses [$i],  $best [$i + 1]
+                   :                       max $$houses [$i] + $best [$i + 2],
+                                                               $best [$i + 1];
+    }
+    $best [0];
 }
 
 
-- 
cgit 


From b7cd81ad7d65fa804a146fbedb56dbf76b8d3a95 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Mon, 7 Feb 2022 18:40:11 +0100
Subject: Week 151: Bash solutions

---
 challenge-151/abigail/bash/ch-1.sh | 41 +++++++++++++++++++++++++++++++++
 challenge-151/abigail/bash/ch-2.sh | 46 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+)
 create mode 100644 challenge-151/abigail/bash/ch-1.sh
 create mode 100644 challenge-151/abigail/bash/ch-2.sh

diff --git a/challenge-151/abigail/bash/ch-1.sh b/challenge-151/abigail/bash/ch-1.sh
new file mode 100644
index 0000000000..eff4fc05e6
--- /dev/null
+++ b/challenge-151/abigail/bash/ch-1.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+
+#
+# Run as: bash ch-1.sh < input-file
+#
+
+set -f
+
+declare -A tree
+
+while read -a tokens
+do    tree=()
+      D=0
+      i=0
+      for token in ${tokens[@]}
+      do  if [ $token == "|" ]
+          then D=$((D + 1))
+               i=0
+          else key=$D,$i
+               if [ $token != "*" ]
+               then tree[$key]=1
+               fi
+               i=$((i + 1))
+          fi
+      done
+
+      for ((d = 0; d <= D; d ++))
+      do  for ((i = 0; i < 2 ** d; i ++))
+          do  if [[   -v tree[$d,$i]                      ]] && \
+                 [[ ! -v tree[$((d + 1)),$((2 * $i))]     ]] && \
+                 [[ ! -v tree[$((d + 1)),$((2 * $i + 1))] ]]
+              then echo $((d + 1))
+                   break 2
+              fi
+          done
+      done
+done
diff --git a/challenge-151/abigail/bash/ch-2.sh b/challenge-151/abigail/bash/ch-2.sh
new file mode 100644
index 0000000000..0b8f213fca
--- /dev/null
+++ b/challenge-151/abigail/bash/ch-2.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+
+#
+# Run as: bash ch-2.sh < input-file
+#
+
+set -f
+
+declare -a best
+
+while read -a houses
+do    if   [[ ${#houses[@]} -lt 2 ]]
+      then echo ${houses[0]}
+           continue
+      fi
+
+      size=${#houses[@]}
+      for  ((i = size - 1; i >= 0; i --))
+      do   ((i1 = i + 1))
+           ((i2 = i + 2))
+           if ((i == size - 1))
+           then best[$i]=${houses[$i]}
+                continue
+           fi
+
+           if ((i == 0))
+           then best[$i]=$((${houses[$i]} + ${best[$i2]}))
+                continue
+           fi
+
+           if   ((i == size - 2))
+           then val1=${houses[$i]}
+                val2=${best[$i1]}
+           else val1=$((${houses[$i]} + ${best[$i2]}))
+                val2=${best[$i1]}
+           fi
+
+           best[$i]=$((val1 < val2 ? val2 : val1))
+      done
+
+      echo ${best[0]}
+done
-- 
cgit 


From e270077b999c4129874da382d77addc76460aa17 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Mon, 7 Feb 2022 20:33:23 +0100
Subject: Week 151: C solutions

---
 challenge-151/abigail/c/ch-1.c | 96 ++++++++++++++++++++++++++++++++++++++++++
 challenge-151/abigail/c/ch-2.c | 62 +++++++++++++++++++++++++++
 2 files changed, 158 insertions(+)
 create mode 100644 challenge-151/abigail/c/ch-1.c
 create mode 100644 challenge-151/abigail/c/ch-2.c

diff --git a/challenge-151/abigail/c/ch-1.c b/challenge-151/abigail/c/ch-1.c
new file mode 100644
index 0000000000..e4487ddaec
--- /dev/null
+++ b/challenge-151/abigail/c/ch-1.c
@@ -0,0 +1,96 @@
+# include <stdlib.h>
+# include <stdio.h>
+# include <string.h>
+# include <stdbool.h>
+# include <ctype.h>
+
+/*
+ * See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+ */
+
+/*
+ * Run as: cc -o ch-1.o ch-1.c; ./ch-1.o < input-file
+ */
+
+int main (void) {
+    char *  line    = NULL;
+    size_t  len     = 0;
+    size_t  str_len;
+
+    while ((str_len = getline (&line, &len, stdin)) != -1) {
+        char * line_ptr = line;
+        /*
+         * Count the number of '|' characters; this determines
+         * how many elements to allocate for our tree.
+         */
+        int size = 3;
+        while (* line_ptr) {
+            if (* line_ptr ++ == '|') {
+                size = 2 * size + 1;
+            }
+        }
+        bool * tree;
+        if ((tree = (bool *) malloc (size * sizeof (bool))) == NULL) {
+            perror ("Malloc tree failed");
+            exit (1);
+        }
+        for (size_t i = 0; i < size; i ++) {
+            tree [i] = false;
+        }
+
+        int D = 0;
+        int i = 0;
+        size_t offset = 0;
+        line_ptr = line;
+        /*
+         * Skip leading spaces
+         */
+        while (* line_ptr && isspace (* line_ptr)) {
+            line_ptr ++;
+        }
+        while (* line_ptr) {
+            if (* line_ptr == '|') {
+                D ++;
+                i = 0;
+                offset = 2 * offset + 1;
+                line_ptr ++;
+                continue;
+            }
+            if (* line_ptr == '*') {
+                i ++;
+                line_ptr ++;
+                continue;
+            }
+            if (isspace (* line_ptr)) {
+                while (* line_ptr && isspace (* line_ptr)) {
+                    line_ptr ++;
+                }
+                continue;
+            }
+            tree [offset + i] = true;
+            i ++;
+            while (* line_ptr && !isspace (* line_ptr) && * line_ptr != '|') {
+                line_ptr ++;
+            }
+        }
+
+        int width = 1;
+        int k     = 0;
+        bool done = false;
+        for (int d = 0; d <= D && !done; d ++) {
+            for (int i = 0; i < width && !done; i ++) {
+                if (tree [k] && !tree [2 * k + 1] && !tree [2 * k + 2]) {
+                    printf ("%d\n", d + 1);
+                    done = true;
+                }
+                k ++;
+            }
+            width *= 2;
+        }
+
+        free (tree);
+    }
+    free (line);
+
+    return (0);
+}
diff --git a/challenge-151/abigail/c/ch-2.c b/challenge-151/abigail/c/ch-2.c
new file mode 100644
index 0000000000..c2a62f6c92
--- /dev/null
+++ b/challenge-151/abigail/c/ch-2.c
@@ -0,0 +1,62 @@
+# include <stdlib.h>
+# include <stdio.h>
+# include <string.h>
+
+/*
+ * See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+ */
+
+/*
+ * Run as: cc -o ch-2.o ch-2.c; ./ch-2.o < input-file
+ */
+
+int max (int a, int b) {
+    return a < b ? b : a;
+}
+
+int main (void) {
+    char *  line    = NULL;
+    size_t  len     = 0;
+    size_t  str_len;
+
+    while ((str_len = getline (&line, &len, stdin)) != -1) {
+        char * line_ptr = line;
+        int * houses = NULL;
+        int * best   = NULL;
+        int val;
+        int offset;
+        int nr_of_houses = 0;
+
+        while (sscanf (line_ptr, "%d%n", &val, &offset) == 1) {
+            if ((houses = (int *)
+                 realloc (houses, ++ nr_of_houses * sizeof (int))) == NULL) {
+                perror ("Recalloc failed");
+                exit (1);
+            }
+            houses [nr_of_houses - 1] = val;
+            line_ptr += offset;
+        }
+
+        if ((best = (int *) malloc (nr_of_houses * sizeof (int))) == NULL) {
+            perror ("Malloc failed");
+            exit (1);
+        }
+
+        for (int i = nr_of_houses - 1; i >= 0; i --) {
+            best [i] = nr_of_houses < 2      ? houses [i]
+                     : i == nr_of_houses - 1 ? houses [i]
+                     : i == 0                ? houses [i]      + best [i + 2]
+                     : i == nr_of_houses - 2 ? max (houses [i],  best [i + 1])
+                     :                         max (houses [i] + best [i + 2],
+                                                                 best [i + 1]);
+        }
+
+        printf ("%d\n", best [0]);
+
+        free (houses);
+        free (best);
+    }
+    free (line);
+
+    return (0);
+}
-- 
cgit 


From f1bc02f8fcc156205b2a8ccabaf0063f32ab8106 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Mon, 7 Feb 2022 22:37:05 +0100
Subject: Week 151: Lua solutions

---
 challenge-151/abigail/lua/ch-1.lua | 45 ++++++++++++++++++++++++++++++++++++++
 challenge-151/abigail/lua/ch-2.lua | 33 ++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+)
 create mode 100644 challenge-151/abigail/lua/ch-1.lua
 create mode 100644 challenge-151/abigail/lua/ch-2.lua

diff --git a/challenge-151/abigail/lua/ch-1.lua b/challenge-151/abigail/lua/ch-1.lua
new file mode 100644
index 0000000000..1d8664060f
--- /dev/null
+++ b/challenge-151/abigail/lua/ch-1.lua
@@ -0,0 +1,45 @@
+#!/opt/local/bin/lua
+
+--
+-- See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+--
+
+--
+-- Run as: lua ch-1.lua < input-file
+--
+
+for line in io . lines () do
+    local tree = {}
+    local d = 1
+    local i = 1
+    tree [d] = {}
+    for token in line : gmatch ("(%S+)") do
+        if token == "|" then
+            d = d + 1
+            i = 1
+            tree [d] = {}
+            goto end_loop
+        end
+        if token == "*" then
+            i = i + 1
+            goto end_loop
+        end
+
+        tree [d] [i] = 1
+        i = i + 1
+
+        ::end_loop::
+    end
+
+    for d, row in ipairs (tree) do
+        for i, _ in pairs (row) do
+            if not tree [d + 1] or
+               not tree [d + 1] [2 * i - 1] and not tree [d + 1] [2 * i] then
+                print (d)
+                goto end_main
+            end
+        end
+    end
+
+    ::end_main::
+end
diff --git a/challenge-151/abigail/lua/ch-2.lua b/challenge-151/abigail/lua/ch-2.lua
new file mode 100644
index 0000000000..98df0aae1d
--- /dev/null
+++ b/challenge-151/abigail/lua/ch-2.lua
@@ -0,0 +1,33 @@
+#!/opt/local/bin/lua
+
+--
+-- See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+--
+
+--
+-- Run as: lua ch-2.lua < input-file
+--
+
+for line in io . lines () do
+    local houses = {}
+    local best   = {}
+    for val in line : gmatch ("%d+") do
+        houses [#houses + 1] = val
+    end
+
+    for i = #houses, 1, -1 do
+        if     2 >= #houses then
+            best [i] =             houses [i]
+        elseif i == #houses then
+            best [i] =             houses [i]
+        elseif i == 0       then
+            best [i] =             houses [i] + best [i + 2]
+        elseif i == #houses - 1 then
+            best [i] = math . max (houses [i],  best [i + 1])
+        else
+            best [i] = math . max (houses [i] + best [i + 2],
+                                                best [i + 1])
+        end
+    end
+    print (best [1])
+end
-- 
cgit 


From dfe3d0c53a5e090bb2784fb9487463656fa72387 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Mon, 7 Feb 2022 23:07:38 +0100
Subject: Week 151: Node.js solutions

---
 challenge-151/abigail/node/ch-1.js | 33 +++++++++++++++++++++++++++++++++
 challenge-151/abigail/node/ch-2.js | 26 ++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 challenge-151/abigail/node/ch-1.js
 create mode 100644 challenge-151/abigail/node/ch-2.js

diff --git a/challenge-151/abigail/node/ch-1.js b/challenge-151/abigail/node/ch-1.js
new file mode 100644
index 0000000000..bf67eda21e
--- /dev/null
+++ b/challenge-151/abigail/node/ch-1.js
@@ -0,0 +1,33 @@
+#!/usr/local/bin/node
+
+//
+// See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+//
+
+//
+// Run as: node ch-1.js < input-file
+//
+
+  require ('readline')
+. createInterface ({input: process . stdin})   
+. on              ('line', line => {
+    let tree = line . split ("\|") . map (row => row . trim () . split (/ +/))
+
+    for (let d = 0; d < tree . length; d ++) {
+        if (d == tree . length - 1) {
+            return
+        }
+        let c_row = tree [d]
+        let n_row = tree [d + 1]
+        for (let i = 0; i < c_row . length; i ++) {
+            let ch1 = 2 * i
+            let ch2 = 2 * i + 1
+            if (c_row [i] != "*"                                   &&
+                     (ch1 >= n_row . length || n_row [ch1] == "*") &&
+                     (ch2 >= n_row . length || n_row [ch2] == "*")) {
+                console . log (d + 1)
+                return;
+            }
+        }
+    }
+})
diff --git a/challenge-151/abigail/node/ch-2.js b/challenge-151/abigail/node/ch-2.js
new file mode 100644
index 0000000000..f4d698ec49
--- /dev/null
+++ b/challenge-151/abigail/node/ch-2.js
@@ -0,0 +1,26 @@
+#!/usr/local/bin/node
+
+//
+// See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+//
+
+//
+// Run as: node ch-2.js < input-file
+//
+
+  require ('readline')
+. createInterface ({input: process . stdin})   
+. on              ('line', line => {
+    let houses = line . trim () . split (/ +/) . map (n => +n)
+    let best   = []
+    for (let i = houses . length - 1; i >= 0; i --) {
+        best [i] =
+            2 >  houses . length     ?             houses [i]
+          : i == houses . length - 1 ?             houses [i]
+          : i == 0                   ?             houses [i] + best [i + 2]
+          : i == houses . length - 2 ? Math . max (houses [i],  best [i + 1])
+          :                            Math . max (houses [i] + best [i + 2],
+                                                                best [i + 1])
+    }
+    console . log (best [0])
+})
-- 
cgit 


From 5045026f0fe4bf7ba93d00350f8bb6bbde68f5be Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Tue, 8 Feb 2022 11:51:15 +0100
Subject: Week 151: Simplified algorithm for part 2.

By adding two dummy 0's to the "best" array, and not bothering the
calculate the best values for the first two houses, we don't have
a case study inside the main loop.
---
 challenge-151/abigail/awk/ch-2.awk | 12 +++++-------
 challenge-151/abigail/bash/ch-2.sh | 34 +++++++---------------------------
 challenge-151/abigail/c/ch-2.c     | 17 ++++++++---------
 challenge-151/abigail/lua/ch-2.lua | 21 +++++++--------------
 challenge-151/abigail/node/ch-2.js | 15 ++++++---------
 challenge-151/abigail/perl/ch-2.pl | 27 ++++++++++-----------------
 6 files changed, 43 insertions(+), 83 deletions(-)

diff --git a/challenge-151/abigail/awk/ch-2.awk b/challenge-151/abigail/awk/ch-2.awk
index 73d9b19812..65428f81e8 100644
--- a/challenge-151/abigail/awk/ch-2.awk
+++ b/challenge-151/abigail/awk/ch-2.awk
@@ -14,13 +14,11 @@ function max (a, b) {
 
 {
     delete best
-    for (i = NF; i > 0; i --) {
-        best [i] = NF <= 2     ? $i                                     \
-                 : i == NF     ? $i                                     \
-                 : i == 1      ? $i     + best [i + 2]                  \
-                 : i == NF - 1 ? max($i,  best [i + 1])                 \
-                 :               max($i + best [i + 2], best [i + 1])
+    best [NF + 1] = 0
+    best [NF + 2] = 0
+    for (i = NF; i > 2; i --) {
+        best [i] = max($i + best [i + 2], best [i + 1])
     }
-    print best [1]
+    print $1 + best [3]
 }
 
diff --git a/challenge-151/abigail/bash/ch-2.sh b/challenge-151/abigail/bash/ch-2.sh
index 0b8f213fca..6a9eceec29 100644
--- a/challenge-151/abigail/bash/ch-2.sh
+++ b/challenge-151/abigail/bash/ch-2.sh
@@ -13,34 +13,14 @@ set -f
 declare -a best
 
 while read -a houses
-do    if   [[ ${#houses[@]} -lt 2 ]]
-      then echo ${houses[0]}
-           continue
-      fi
-
-      size=${#houses[@]}
-      for  ((i = size - 1; i >= 0; i --))
-      do   ((i1 = i + 1))
-           ((i2 = i + 2))
-           if ((i == size - 1))
-           then best[$i]=${houses[$i]}
-                continue
-           fi
-
-           if ((i == 0))
-           then best[$i]=$((${houses[$i]} + ${best[$i2]}))
-                continue
-           fi
-
-           if   ((i == size - 2))
-           then val1=${houses[$i]}
-                val2=${best[$i1]}
-           else val1=$((${houses[$i]} + ${best[$i2]}))
-                val2=${best[$i1]}
-           fi
-
+do    size=${#houses[@]}
+      best[$((size + 0))]=0
+      best[$((size + 1))]=0
+      for  ((i = size - 1; i >= 2; i --))
+      do   ((val1 = ${houses[$i]} + ${best[$((i + 2))]}))
+           ((val2 = ${best[$((i + 1))]}))
            best[$i]=$((val1 < val2 ? val2 : val1))
       done
 
-      echo ${best[0]}
+      echo $((${houses[0]} + ${best[2]}))
 done
diff --git a/challenge-151/abigail/c/ch-2.c b/challenge-151/abigail/c/ch-2.c
index c2a62f6c92..34e7e24ac1 100644
--- a/challenge-151/abigail/c/ch-2.c
+++ b/challenge-151/abigail/c/ch-2.c
@@ -37,21 +37,20 @@ int main (void) {
             line_ptr += offset;
         }
 
-        if ((best = (int *) malloc (nr_of_houses * sizeof (int))) == NULL) {
+        if ((best = (int *)
+             malloc ((nr_of_houses + 2) * sizeof (int))) == NULL) {
             perror ("Malloc failed");
             exit (1);
         }
 
-        for (int i = nr_of_houses - 1; i >= 0; i --) {
-            best [i] = nr_of_houses < 2      ? houses [i]
-                     : i == nr_of_houses - 1 ? houses [i]
-                     : i == 0                ? houses [i]      + best [i + 2]
-                     : i == nr_of_houses - 2 ? max (houses [i],  best [i + 1])
-                     :                         max (houses [i] + best [i + 2],
-                                                                 best [i + 1]);
+        best [nr_of_houses + 0] = 0;
+        best [nr_of_houses + 1] = 0;
+
+        for (int i = nr_of_houses - 1; i >= 2; i --) {
+            best [i] = max (houses [i] + best [i + 2], best [i + 1]);
         }
 
-        printf ("%d\n", best [0]);
+        printf ("%d\n", houses [0] + best [2]);
 
         free (houses);
         free (best);
diff --git a/challenge-151/abigail/lua/ch-2.lua b/challenge-151/abigail/lua/ch-2.lua
index 98df0aae1d..0e644d0a6c 100644
--- a/challenge-151/abigail/lua/ch-2.lua
+++ b/challenge-151/abigail/lua/ch-2.lua
@@ -15,19 +15,12 @@ for line in io . lines () do
         houses [#houses + 1] = val
     end
 
-    for i = #houses, 1, -1 do
-        if     2 >= #houses then
-            best [i] =             houses [i]
-        elseif i == #houses then
-            best [i] =             houses [i]
-        elseif i == 0       then
-            best [i] =             houses [i] + best [i + 2]
-        elseif i == #houses - 1 then
-            best [i] = math . max (houses [i],  best [i + 1])
-        else
-            best [i] = math . max (houses [i] + best [i + 2],
-                                                best [i + 1])
-        end
+    best [#houses + 1] = 0
+    best [#houses + 2] = 0
+
+    for i = #houses, 3, -1 do
+        best [i] = math . max (houses [i] + best [i + 2], best [i + 1])
     end
-    print (best [1])
+
+    print (houses [1] + best [3])
 end
diff --git a/challenge-151/abigail/node/ch-2.js b/challenge-151/abigail/node/ch-2.js
index f4d698ec49..079c61e0ce 100644
--- a/challenge-151/abigail/node/ch-2.js
+++ b/challenge-151/abigail/node/ch-2.js
@@ -13,14 +13,11 @@
 . on              ('line', line => {
     let houses = line . trim () . split (/ +/) . map (n => +n)
     let best   = []
-    for (let i = houses . length - 1; i >= 0; i --) {
-        best [i] =
-            2 >  houses . length     ?             houses [i]
-          : i == houses . length - 1 ?             houses [i]
-          : i == 0                   ?             houses [i] + best [i + 2]
-          : i == houses . length - 2 ? Math . max (houses [i],  best [i + 1])
-          :                            Math . max (houses [i] + best [i + 2],
-                                                                best [i + 1])
+    let size   = houses . length
+    best [size + 0] = 0
+    best [size + 1] = 0
+    for (let i = size - 1; i >= 2; i --) {
+        best [i] = Math . max (houses [i] + best [i + 2], best [i + 1])
     }
-    console . log (best [0])
+    console . log (houses [0] + best [2])
 })
diff --git a/challenge-151/abigail/perl/ch-2.pl b/challenge-151/abigail/perl/ch-2.pl
index 5f5519381f..9c1e1d3b60 100644
--- a/challenge-151/abigail/perl/ch-2.pl
+++ b/challenge-151/abigail/perl/ch-2.pl
@@ -26,29 +26,22 @@ use List::Util qw [max];
 # the value of the current house, plus the maximum we can get
 # if we started two houses down. The maximum value we can get by
 # not robbing this house is the best we can get by starting from
-# the next house.
+# the next house. We'll add two empty houses to make everything work
+# out nicely.
 #
-# We need some fiddling around the edges:
-#    - Maximizing the value starting from the last house is by robbing it.
-#    - Maximizing the value starting from the penultimate house is
-#      robbing the most valuable of the last two houses.
-#    - If there are only two houses, rob the current house.
-#    - The first house should always be robbed (a requirement); the
-#      maximum value which can be achieved we get by starting from the
-#      third house, adding the value of the first.
+# Note that we don't have to calculate the best option starting
+# from the second house, as we will always skip the second house.
+# And we must always pick the first house.
 #
 
 sub best ($houses) {
     my @best;
-    foreach my $i (reverse keys @$houses) {
-        $best [$i] = @$houses < 2        ?     $$houses [$i]
-                   : $i == $#$houses     ?     $$houses [$i]
-                   : $i == 0             ?     $$houses [$i] + $best [$i + 2]
-                   : $i == $#$houses - 1 ? max $$houses [$i],  $best [$i + 1]
-                   :                       max $$houses [$i] + $best [$i + 2],
-                                                               $best [$i + 1];
+    $best [$#$houses + 1] = 0;
+    $best [$#$houses + 2] = 0;
+    for (my $i = $#$houses; $i >= 2; $i --) {
+        $best [$i] = max $$houses [$i] + $best [$i + 2], $best [$i + 1];
     }
-    $best [0];
+    $$houses [0] + $best [2];
 }
 
 
-- 
cgit 


From acbd8f6b2a7471edbe77f9ea08ab82db66e1c304 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Tue, 8 Feb 2022 15:12:14 +0100
Subject: Week 151: Python solutions

---
 challenge-151/abigail/python/ch-1.py | 32 ++++++++++++++++++++++++++++++++
 challenge-151/abigail/python/ch-2.py | 18 ++++++++++++++++++
 2 files changed, 50 insertions(+)
 create mode 100644 challenge-151/abigail/python/ch-1.py
 create mode 100644 challenge-151/abigail/python/ch-2.py

diff --git a/challenge-151/abigail/python/ch-1.py b/challenge-151/abigail/python/ch-1.py
new file mode 100644
index 0000000000..12dec88d86
--- /dev/null
+++ b/challenge-151/abigail/python/ch-1.py
@@ -0,0 +1,32 @@
+#!/usr/local/bin/python3
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+
+#
+# Run as: python ch-1.py < input-file
+#
+
+import fileinput
+
+for line in fileinput . input ():
+    tree = list (map (lambda row: row . strip () . split (),
+                                 line . strip () . split ("|")))
+    for d in range (len (tree)):
+        if (d == len (tree) - 1):
+            print (d + 1)
+            break
+        done = False
+        for i in range (len (tree [d])):
+            if tree [d] [i] != "*":
+                ch1 = 2 * i
+                ch2 = 2 * i + 1
+                if ch1 >= len (tree [d + 1]) or (
+                    (tree [d + 1] [ch1] == "*" and (
+                      ch2 >= len (tree [d + 1]) or tree [d + 1] [ch2] == "*"))):
+                    print (d + 1)
+                    done = True
+                    break
+        if done:
+            break
diff --git a/challenge-151/abigail/python/ch-2.py b/challenge-151/abigail/python/ch-2.py
new file mode 100644
index 0000000000..a20a18329b
--- /dev/null
+++ b/challenge-151/abigail/python/ch-2.py
@@ -0,0 +1,18 @@
+#!/usr/local/bin/python3
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+
+#
+# Run as: python ch-2.py < input-file
+#
+
+import fileinput
+
+for line in fileinput . input ():
+    houses = list (map (lambda x: int (x), line . strip () . split ()))
+    best   = [0] * (len (houses) + 2)
+    for i in range (len (houses) - 1, 1, -1):
+        best [i] = max (houses [i] + best [i + 2], best [i + 1])
+    print (houses [0] + best [2])
-- 
cgit 


From c6bb015992c65d4248161ca12c22a1af6dd29711 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Tue, 8 Feb 2022 18:33:35 +0100
Subject: Week 151: Make the algorithm for part 2 even simpler.

No need for an additional array: add two 0's to the array of
valuables, and modify in situ.
---
 challenge-151/abigail/awk/ch-2.awk   |  7 ++-----
 challenge-151/abigail/bash/ch-2.sh   | 19 ++++++++-----------
 challenge-151/abigail/c/ch-2.c       | 29 ++++++++++-------------------
 challenge-151/abigail/lua/ch-2.lua   | 15 +++++++--------
 challenge-151/abigail/node/ch-2.js   | 14 ++++++--------
 challenge-151/abigail/perl/ch-2.pl   | 15 +++++----------
 challenge-151/abigail/python/ch-2.py | 11 ++++++-----
 7 files changed, 44 insertions(+), 66 deletions(-)

diff --git a/challenge-151/abigail/awk/ch-2.awk b/challenge-151/abigail/awk/ch-2.awk
index 65428f81e8..732444708f 100644
--- a/challenge-151/abigail/awk/ch-2.awk
+++ b/challenge-151/abigail/awk/ch-2.awk
@@ -13,12 +13,9 @@ function max (a, b) {
 }
 
 {
-    delete best
-    best [NF + 1] = 0
-    best [NF + 2] = 0
     for (i = NF; i > 2; i --) {
-        best [i] = max($i + best [i + 2], best [i + 1])
+        $i = max($i + $(i + 2), $(i + 1))
     }
-    print $1 + best [3]
+    print $1 + $3
 }
 
diff --git a/challenge-151/abigail/bash/ch-2.sh b/challenge-151/abigail/bash/ch-2.sh
index 6a9eceec29..cb009e0e16 100644
--- a/challenge-151/abigail/bash/ch-2.sh
+++ b/challenge-151/abigail/bash/ch-2.sh
@@ -10,17 +10,14 @@
 
 set -f
 
-declare -a best
-
-while read -a houses
-do    size=${#houses[@]}
-      best[$((size + 0))]=0
-      best[$((size + 1))]=0
-      for  ((i = size - 1; i >= 2; i --))
-      do   ((val1 = ${houses[$i]} + ${best[$((i + 2))]}))
-           ((val2 = ${best[$((i + 1))]}))
-           best[$i]=$((val1 < val2 ? val2 : val1))
+while read -a h
+do    h[${#h[@]}]=0
+      h[${#h[@]}]=0
+      for  ((i = ${#h[@]} - 3; i >= 2; i --))
+      do   ((val1 = ${h[$i]} + ${h[$((i + 2))]}))
+           ((val2 = ${h[$((i + 1))]}))
+           h[$i]=$((val1 < val2 ? val2 : val1))
       done
 
-      echo $((${houses[0]} + ${best[2]}))
+      echo $((${h[0]} + ${h[2]}))
 done
diff --git a/challenge-151/abigail/c/ch-2.c b/challenge-151/abigail/c/ch-2.c
index 34e7e24ac1..9c46968f80 100644
--- a/challenge-151/abigail/c/ch-2.c
+++ b/challenge-151/abigail/c/ch-2.c
@@ -21,39 +21,30 @@ int main (void) {
 
     while ((str_len = getline (&line, &len, stdin)) != -1) {
         char * line_ptr = line;
-        int * houses = NULL;
-        int * best   = NULL;
+        int * h = NULL;
         int val;
         int offset;
-        int nr_of_houses = 0;
+        int sz = 0;
 
         while (sscanf (line_ptr, "%d%n", &val, &offset) == 1) {
-            if ((houses = (int *)
-                 realloc (houses, ++ nr_of_houses * sizeof (int))) == NULL) {
+            if ((h = (int *) realloc (h, (2 + ++ sz) * sizeof (int))) == NULL) {
                 perror ("Recalloc failed");
                 exit (1);
             }
-            houses [nr_of_houses - 1] = val;
+            h [sz - 1] = val;
             line_ptr += offset;
         }
 
-        if ((best = (int *)
-             malloc ((nr_of_houses + 2) * sizeof (int))) == NULL) {
-            perror ("Malloc failed");
-            exit (1);
-        }
-
-        best [nr_of_houses + 0] = 0;
-        best [nr_of_houses + 1] = 0;
+        h [sz + 0] = 0;
+        h [sz + 1] = 0;
 
-        for (int i = nr_of_houses - 1; i >= 2; i --) {
-            best [i] = max (houses [i] + best [i + 2], best [i + 1]);
+        for (int i = sz - 1; i >= 2; i --) {
+            h [i] = max (h [i] + h [i + 2], h [i + 1]);
         }
 
-        printf ("%d\n", houses [0] + best [2]);
+        printf ("%d\n", h [0] + h [2]);
 
-        free (houses);
-        free (best);
+        free (h);
     }
     free (line);
 
diff --git a/challenge-151/abigail/lua/ch-2.lua b/challenge-151/abigail/lua/ch-2.lua
index 0e644d0a6c..d8ac15c101 100644
--- a/challenge-151/abigail/lua/ch-2.lua
+++ b/challenge-151/abigail/lua/ch-2.lua
@@ -9,18 +9,17 @@
 --
 
 for line in io . lines () do
-    local houses = {}
-    local best   = {}
+    local h = {}
     for val in line : gmatch ("%d+") do
-        houses [#houses + 1] = val
+        h [#h + 1] = val
     end
 
-    best [#houses + 1] = 0
-    best [#houses + 2] = 0
+    h [#h + 1] = 0
+    h [#h + 1] = 0
 
-    for i = #houses, 3, -1 do
-        best [i] = math . max (houses [i] + best [i + 2], best [i + 1])
+    for i = #h - 2, 3, -1 do
+        h [i] = math . max (h [i] + h [i + 2], h [i + 1])
     end
 
-    print (houses [1] + best [3])
+    print (h [1] + h [3])
 end
diff --git a/challenge-151/abigail/node/ch-2.js b/challenge-151/abigail/node/ch-2.js
index 079c61e0ce..11a88c6bc7 100644
--- a/challenge-151/abigail/node/ch-2.js
+++ b/challenge-151/abigail/node/ch-2.js
@@ -11,13 +11,11 @@
   require ('readline')
 . createInterface ({input: process . stdin})   
 . on              ('line', line => {
-    let houses = line . trim () . split (/ +/) . map (n => +n)
-    let best   = []
-    let size   = houses . length
-    best [size + 0] = 0
-    best [size + 1] = 0
-    for (let i = size - 1; i >= 2; i --) {
-        best [i] = Math . max (houses [i] + best [i + 2], best [i + 1])
+    let h = line . trim () . split (/ +/) . map (n => +n)
+    h [h . length] = 0
+    h [h . length] = 0
+    for (let i = h . length - 3; i >= 2; i --) {
+        h [i] = Math . max (h [i] + h [i + 2], h [i + 1])
     }
-    console . log (houses [0] + best [2])
+    console . log (h [0] + h [2])
 })
diff --git a/challenge-151/abigail/perl/ch-2.pl b/challenge-151/abigail/perl/ch-2.pl
index 9c1e1d3b60..df731f4cfe 100644
--- a/challenge-151/abigail/perl/ch-2.pl
+++ b/challenge-151/abigail/perl/ch-2.pl
@@ -34,15 +34,10 @@ use List::Util qw [max];
 # And we must always pick the first house.
 #
 
-sub best ($houses) {
-    my @best;
-    $best [$#$houses + 1] = 0;
-    $best [$#$houses + 2] = 0;
-    for (my $i = $#$houses; $i >= 2; $i --) {
-        $best [$i] = max $$houses [$i] + $best [$i + 2], $best [$i + 1];
-    }
-    $$houses [0] + $best [2];
+while (<>) {
+    my @h = (/[0-9]+/g, 0, 0);
+    $h [$_] = max $h [$_] + $h [$_ + 2], $h [$_ + 1] for reverse 2 .. $#h - 2;
+    say $h [0] + $h [2];
 }
 
-
-say best [/[0-9]+/g] while <>;
+__END__
diff --git a/challenge-151/abigail/python/ch-2.py b/challenge-151/abigail/python/ch-2.py
index a20a18329b..52522eff0b 100644
--- a/challenge-151/abigail/python/ch-2.py
+++ b/challenge-151/abigail/python/ch-2.py
@@ -11,8 +11,9 @@
 import fileinput
 
 for line in fileinput . input ():
-    houses = list (map (lambda x: int (x), line . strip () . split ()))
-    best   = [0] * (len (houses) + 2)
-    for i in range (len (houses) - 1, 1, -1):
-        best [i] = max (houses [i] + best [i + 2], best [i + 1])
-    print (houses [0] + best [2])
+    h = list (map (lambda x: int (x), line . strip () . split ()))
+    h . append (0)
+    h . append (0)
+    for i in range (len (h) - 3, 1, -1):
+        h [i] = max (h [i] + h [i + 2], h [i + 1])
+    print (h [0] + h [2])
-- 
cgit 


From 922b81eeb7516829d0311fd3fb5b9fa51fe48876 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Tue, 8 Feb 2022 19:14:23 +0100
Subject: Week 151: Ruby solutions

---
 challenge-151/abigail/ruby/ch-1.rb | 31 +++++++++++++++++++++++++++++++
 challenge-151/abigail/ruby/ch-2.rb | 17 +++++++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 challenge-151/abigail/ruby/ch-1.rb
 create mode 100644 challenge-151/abigail/ruby/ch-2.rb

diff --git a/challenge-151/abigail/ruby/ch-1.rb b/challenge-151/abigail/ruby/ch-1.rb
new file mode 100644
index 0000000000..1164c5bdfc
--- /dev/null
+++ b/challenge-151/abigail/ruby/ch-1.rb
@@ -0,0 +1,31 @@
+#!/usr/bin/ruby
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+ 
+#
+# Run as: ruby ch-1.rb < input-file
+#
+
+ARGF . each_line do |line|
+    tree = line . strip() . split(/\|/) . map do |row|
+        row . strip() . split(/ +/) . map do |x|
+            x == "*" ? false : true
+        end
+    end
+    done = false
+    for d in 0 .. tree . length() - 1 do
+        for i in 0 .. tree [d] . length() - 1 do
+            if tree [d] [i] && !tree [d + 1] [2 * i] &&
+                               !tree [d + 1] [2 * i + 1] then
+                puts (d + 1)
+                done = true
+                break
+            end
+        end
+        if done then
+            break
+        end
+    end
+end
diff --git a/challenge-151/abigail/ruby/ch-2.rb b/challenge-151/abigail/ruby/ch-2.rb
new file mode 100644
index 0000000000..ebdd805af5
--- /dev/null
+++ b/challenge-151/abigail/ruby/ch-2.rb
@@ -0,0 +1,17 @@
+#!/usr/bin/ruby
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+ 
+#
+# Run as: ruby ch-2.rb < input-file
+#
+
+ARGF . each_line do |line|
+    (h = line . split . map do |n| n . to_i end) . push(0, 0)
+    (h . length - 3) . downto(2) do |i|
+        h[i] = [h[i] + h[i + 2], h[i + 1]] . max
+    end
+    puts (h[0] + h[2])
+end
-- 
cgit 


From d77e2b954262d6a2299587cc83d572caa879b3de Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Tue, 8 Feb 2022 20:25:30 +0100
Subject: Week 151: Go solution for part 2

---
 challenge-151/abigail/go/ch-2.go | 48 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 challenge-151/abigail/go/ch-2.go

diff --git a/challenge-151/abigail/go/ch-2.go b/challenge-151/abigail/go/ch-2.go
new file mode 100644
index 0000000000..a8b6725ffa
--- /dev/null
+++ b/challenge-151/abigail/go/ch-2.go
@@ -0,0 +1,48 @@
+package main
+
+//
+// See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+//
+
+//
+// Run as: go run ch-2.go < input-file
+//
+
+import (
+    "fmt"
+    "bufio"
+    "os"
+    "strconv"
+    "strings"
+)
+
+func max (a int, b int) int {
+    if a < b {
+        return b
+    }
+    return a
+}
+
+func main () {
+    var reader = bufio . NewReader (os. Stdin)
+    for {
+        var text, err = reader . ReadString ('\n')
+        if (err != nil) {
+            break
+        }
+
+        s := strings . Fields (strings . Trim (text, "\n"))
+        h := make ([] int, len (s))
+        for i, v := range s {
+            n, _ := strconv . Atoi (v)
+            h [i] = n
+        }
+        h = append (h, 0, 0)
+
+        for i := len (h) - 3; i >= 2; i -- {
+            h [i] = max (h [i] + h [i + 2], h [i + 1])
+        }
+
+        fmt . Println (h [0] + h [2])
+    }
+}
-- 
cgit 


From c505ea725b0c148e1c8017b282d7f6b48a8236d8 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Tue, 8 Feb 2022 20:41:01 +0100
Subject: Week 151: R solution for part 2

---
 challenge-151/abigail/r/ch-2.r | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 challenge-151/abigail/r/ch-2.r

diff --git a/challenge-151/abigail/r/ch-2.r b/challenge-151/abigail/r/ch-2.r
new file mode 100644
index 0000000000..5d2e166d4a
--- /dev/null
+++ b/challenge-151/abigail/r/ch-2.r
@@ -0,0 +1,22 @@
+#!/usr/local/bin/Rscript
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+#
+
+#
+# Run as: Rscript ch-2.r < input-file
+#
+
+stdin <- file ('stdin', 'r')
+repeat {
+    line <- readLines (stdin, n = 1)
+    if (length (line) == 0) {
+        break
+    }
+    h <- c (as.numeric (strsplit (line, " ") [[1]]), 0, 0)
+    for (i in seq (length (h) - 2, 3, -1)) {
+        h [[i]] <- max (c (h [[i]] + h [[i + 2]], h [[i + 1]]))
+    }
+    cat (h [[1]] + h [[3]], "\n")
+}
-- 
cgit 


From 0622db52478d8591387acd183d27d3fb19f5334f Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Tue, 8 Feb 2022 20:42:39 +0100
Subject: Week 151: README

---
 challenge-151/abigail/README.md | 27 ---------------------------
 1 file changed, 27 deletions(-)

diff --git a/challenge-151/abigail/README.md b/challenge-151/abigail/README.md
index 352bb54018..f1c6532822 100644
--- a/challenge-151/abigail/README.md
+++ b/challenge-151/abigail/README.md
@@ -4,50 +4,23 @@
 
 * [AWK](awk/ch-1.awk)
 * [Bash](bash/ch-1.sh)
-* [Bc](bc/ch-1.bc)
 * [C](c/ch-1.c)
-* [Go](go/ch-1.go)
-* [Java](java/ch-1.java)
 * [Lua](lua/ch-1.lua)
 * [Node.js](node/ch-1.js)
-* [Pascal](pascal/ch-1.p)
 * [Perl](perl/ch-1.pl)
 * [Python](python/ch-1.py)
-* [R](r/ch-1.r)
 * [Ruby](ruby/ch-1.rb)
-* [Scheme](scheme/ch-1.scm)
-* [Tcl](tcl/ch-1.tcl)
 
 
 ## Part 2
 
 * [AWK](awk/ch-2.awk)
 * [Bash](bash/ch-2.sh)
-* [Basic](basic/ch-2.bas)
-* [Bc](bc/ch-2.bc)
-* [Befunge-93](befunge-93/ch-2.bf93)
 * [C](c/ch-2.c)
-* [Cobol](cobol/ch-2.cb)
-* [Csh](csh/ch-2.csh)
-* [Erlang](lua/ch-2.erl)
-* [Forth](lua/ch-2.fs)
-* [Fortran](fortran/ch-2.f90)
 * [Go](go/ch-2.go)
-* [Java](java/ch-2.java)
 * [Lua](lua/ch-2.lua)
-* [m4](m4/ch-2.m4)
-* [MMIX](mmix/ch-2.mms)
 * [Node.js](node/ch-2.js)
-* [OCaml](ocaml/ch-2.ml)
-* [Pascal](pascal/ch-2.p)
 * [Perl](perl/ch-2.pl)
-* [PHP](php/ch-2.php)
-* [PostScript](postscript/ch-2.ps)
 * [Python](python/ch-2.py)
 * [R](r/ch-2.r)
-* [Rexx](rexx/ch-2.rexx)
 * [Ruby](ruby/ch-2.rb)
-* [Scheme](scheme/ch-2.scm)
-* [Sed](sed/ch-2.sed)
-* [SQL](sql/ch-2.sql)
-* [Tcl](tcl/ch-2.tcl)
-- 
cgit 


From a09d0dd70c22dc386c4280cfae04158098dcc924 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.freedom.nl>
Date: Tue, 8 Feb 2022 20:59:09 +0100
Subject: Week 151: Pascal solution for part 2

---
 challenge-151/abigail/README.md     |  1 +
 challenge-151/abigail/pascal/ch-2.p | 41 +++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 challenge-151/abigail/pascal/ch-2.p

diff --git a/challenge-151/abigail/README.md b/challenge-151/abigail/README.md
index f1c6532822..870c6804c1 100644
--- a/challenge-151/abigail/README.md
+++ b/challenge-151/abigail/README.md
@@ -20,6 +20,7 @@
 * [Go](go/ch-2.go)
 * [Lua](lua/ch-2.lua)
 * [Node.js](node/ch-2.js)
+* [Pascal](pascal/ch-2.p)
 * [Perl](perl/ch-2.pl)
 * [Python](python/ch-2.py)
 * [R](r/ch-2.r)
diff --git a/challenge-151/abigail/pascal/ch-2.p b/challenge-151/abigail/pascal/ch-2.p
new file mode 100644
index 0000000000..18053673e2
--- /dev/null
+++ b/challenge-151/abigail/pascal/ch-2.p
@@ -0,0 +1,41 @@
+Program ch2;
+
+(*                                                                   *)
+(* See https://theweeklychallenge.org/blog/perl-weekly-challenge-151 *)
+(*                                                                   *)
+
+(*                                                        *)
+(* Run as: fpc -och-2.out ch-2.p; ./ch-2.out < input-file *)
+(*                                                        *)
+
+uses
+    math;
+
+var
+    h: array of integer;
+    i, sz: integer;
+
+begin
+    while not eof do begin
+        sz := 0;
+        setlength (h, sz);
+
+        while not eoln do begin
+            inc (sz);
+            setlength (h, sz);
+            read (h [sz - 1]);
+        end;
+
+        setlength (h, sz + 2);
+        h [sz + 0] := 0;
+        h [sz + 1] := 0;
+
+        for i := sz - 1 downto 2 do begin
+            h [i] := max (h [i] + h [i + 2], h [i + 1]);
+        end;
+
+        writeln (h [0] + h [2]);
+
+        readln;
+    end
+end.
-- 
cgit