RogerBW solutions for challenge no. 206

13 files changed, 668 insertions, 0 deletions

diff --git a/challenge-206/roger-bell-west/perl/ch-1.pl b/challenge-206/roger-bell-west/perl/ch-1.pl
new file mode 100755
index 0000000000..0ec8a1447c
--- /dev/null
+++ b/challenge-206/roger-bell-west/perl/ch-1.pl
@@ -0,0 +1,27 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 3;
+
+is(shortesttime(['00:00', '23:55', '20:00']), 5, 'example 1');
+is(shortesttime(['01:01', '00:50', '00:57']), 4, 'example 2');
+is(shortesttime(['10:10', '09:30', '09:00', '09:55']), 15, 'example 3');
+
+use Algorithm::Combinatorics qw(combinations);
+use List::Util qw(min);
+
+sub shortesttime($n) {
+  my $dl = 1440;
+  my @nl = map {/(\d+):(\d+)/; 60*$1+$2} @{$n};
+  my $i = combinations(\@nl, 2);
+  my @o;
+  while (my $p = $i->next) {
+    my $d = abs($p->[0] - $p->[1]);
+    push @o, $d;
+    push @o, $dl - $d;
+  }
+  return min(@o);
+}
diff --git a/challenge-206/roger-bell-west/perl/ch-2.pl b/challenge-206/roger-bell-west/perl/ch-2.pl
new file mode 100755
index 0000000000..570dc5257b
--- /dev/null
+++ b/challenge-206/roger-bell-west/perl/ch-2.pl
@@ -0,0 +1,37 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use experimental 'signatures';
+
+use Test::More tests => 2;
+
+is(arraypairing([1, 2, 3, 4]), 4, 'example 1');
+is(arraypairing([0, 2, 1, 3]), 2, 'example 2');
+
+use Algorithm::Combinatorics qw(combinations permutations);
+use List::Util qw(min max);
+
+sub arraypairing($n) {
+  my $nl = scalar @{$n};
+  if ($nl % 2 == 1) {
+    return 0;
+  }
+  my $hl = $nl / 2;
+  my @out;
+  my $ic = combinations([0 .. $nl-1], $hl);
+  while (my $px = $ic->next) {
+    my @pa = map {$n->[$_]} @{$px};
+    my %ps = map {$_ => 1} @{$px};
+    my @pb = map {$n->[$_]} grep {!exists $ps{$_}} (0 .. $nl-1);
+    my $ip = permutations(\@pa);
+    while (my $pp = $ip->next) {
+      my $s = 0;
+      foreach my $i (0 .. $hl-1) {
+        $s += min($pp->[$i], $pb[$i]);
+      }
+      push @out,$s;
+    }
+  }
+  return max(@out);
+}
diff --git a/challenge-206/roger-bell-west/postscript/ch-1.ps b/challenge-206/roger-bell-west/postscript/ch-1.ps
new file mode 100644
index 0000000000..371ba76a41
--- /dev/null
+++ b/challenge-206/roger-bell-west/postscript/ch-1.ps
@@ -0,0 +1,105 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/reduce { % array proc -> value
+    2 dict begin
+    /p exch def
+    /a exch def
+    a 0 get
+    1 1 a length 1 sub {
+        a exch get
+        p
+    } for
+    end
+} bind def
+
+/test.end {
+    ( ) print
+    test.count 0 gt {
+        (Passed ) print
+        test.pass (...) cvs print
+        (/) print
+        test.count (...) cvs print
+        ( \() print
+        test.pass 100 mul test.count idiv (...) cvs print
+        (%\)) print
+        (\r\n) print
+    } if
+} bind def
+
+/listmin {
+    { min } reduce
+} bind def
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+/combinations {
+    4 dict begin
+    /k exch def
+    /arr exch def
+    /c [
+        0 1 k 1 sub { } for
+        arr length
+        0
+    ] def
+    [
+        {
+            [
+                k 1 sub -1 0 {
+                    c exch get arr exch get
+                } for
+            ]
+            /j 0 def
+            {
+                c j get 1 add c j 1 add get ne {
+                    exit
+                } if
+                c j j put
+                /j j 1 add def
+            } loop
+            j k ge {
+                exit
+            } if
+            c j c j get 1 add put
+        } loop
+    ]
+    end
+} bind def
+
+/test {
+    /test.count test.count 1 add def
+    {
+        /test.pass test.pass 1 add def
+    } {
+        ( ) print
+        test.count (....) cvs print
+        (-fail) print
+    } ifelse
+} bind def
+
+
+% end included library code
+
+/shortesttime {
+    [ exch
+      {
+          dup 0 2 getinterval cvi 60 mul exch 3 2 getinterval cvi add
+      } forall
+    ]
+    [ exch
+      2 combinations {
+          aload pop sub abs dup 1440 exch sub
+      } forall
+    ] listmin
+} bind def
+
+(shortesttime) test.start
+[(00:00) (23:55) (20:00)] shortesttime 5 eq test
+[(01:01) (00:50) (00:57)] shortesttime 4 eq test
+[(10:10) (09:30) (09:00) (09:55)] shortesttime 15 eq test
+test.end
diff --git a/challenge-206/roger-bell-west/postscript/ch-2.ps b/challenge-206/roger-bell-west/postscript/ch-2.ps
new file mode 100644
index 0000000000..c1a53697c2
--- /dev/null
+++ b/challenge-206/roger-bell-west/postscript/ch-2.ps
@@ -0,0 +1,199 @@
+%!PS
+
+% begin included library code
+% see https://codeberg.org/Firedrake/postscript-libraries/
+/test {
+    /test.count test.count 1 add def
+    {
+        /test.pass test.pass 1 add def
+    } {
+        ( ) print
+        test.count (....) cvs print
+        (-fail) print
+    } ifelse
+} bind def
+
+/test.start {
+    print (:) print
+    /test.pass 0 def
+    /test.count 0 def
+} bind def
+
+/combinations {
+    4 dict begin
+    /k exch def
+    /arr exch def
+    /c [
+        0 1 k 1 sub { } for
+        arr length
+        0
+    ] def
+    [
+        {
+            [
+                k 1 sub -1 0 {
+                    c exch get arr exch get
+                } for
+            ]
+            /j 0 def
+            {
+                c j get 1 add c j 1 add get ne {
+                    exit
+                } if
+                c j j put
+                /j j 1 add def
+            } loop
+            j k ge {
+                exit
+            } if
+            c j c j get 1 add put
+        } loop
+    ]
+    end
+} bind def
+
+/map { % array proc -> array
+    2 dict begin
+    /p exch def
+    [ exch
+      {
+          p
+      } forall
+    ]
+    end
+} bind def
+
+/reduce { % array proc -> value
+    2 dict begin
+    /p exch def
+    /a exch def
+    a 0 get
+    1 1 a length 1 sub {
+        a exch get
+        p
+    } for
+    end
+} bind def
+
+/permute { % [array] {proc} permute runs proc on each permutation of array
+    7 dict begin
+    /permute.subproc exch def
+    /permute.a exch def
+    /permute.n permute.a length def
+    /permute.c [ permute.n { 0 } repeat ] def
+    permute.a permute.subproc
+    /permute.i 0 def
+    {
+        permute.i permute.n ge {
+            exit
+        } if
+        permute.c permute.i get permute.i lt {
+            permute.i 2 mod 0 eq {
+                0 permute.i permute.swap
+            } {
+                permute.c permute.i get permute.i permute.swap
+            } ifelse
+            permute.a permute.subproc
+            permute.c permute.i get 1 add permute.c exch permute.i exch put
+            /permute.i 0 def
+        } {
+            permute.c permute.i 0 put
+            /permute.i permute.i 1 add def
+        } ifelse
+    } loop
+    end
+} bind def
+
+/test.end {
+    ( ) print
+    test.count 0 gt {
+        (Passed ) print
+        test.pass (...) cvs print
+        (/) print
+        test.count (...) cvs print
+        ( \() print
+        test.pass 100 mul test.count idiv (...) cvs print
+        (%\)) print
+        (\r\n) print
+    } if
+} bind def
+
+/filter { % array proc(bool) -> array
+    1 dict begin
+    /p exch def
+    [ exch
+      {
+          dup p not
+          {
+              pop
+          } if
+      } forall
+    ]
+    end
+} bind def
+
+/permute.swap {
+    /permute.bi exch def
+    /permute.ai exch def
+    permute.a permute.ai get
+    permute.a permute.bi get
+    permute.a exch permute.ai exch put
+    permute.a exch permute.bi exch put
+} bind def
+
+/toset { % array -> dict of (value, true)
+    << exch
+       {
+           true
+       } forall
+    >>
+} bind def
+
+/listmax {
+    { max } reduce
+} bind def
+
+
+% end included library code
+
+/arraypairing {
+    9 dict begin
+    /n exch def
+    /nl n length def
+    nl 2 mod 1 eq {
+        0
+    } {
+        /hl nl 2 idiv def
+        [
+            [ 0 1 nl 1 sub {} for ]
+            hl
+            combinations {
+                /px exch def
+                /pa [
+                    px {
+                        n exch get
+                    } forall
+                ] def
+                /ps px toset def
+                /pb [ 0 1 nl 1 sub {} for ]
+                { ps exch known not } filter
+                { n exch get } map def
+                pa {
+                    /pp exch def
+                    /s 0 def
+                    0 1 hl 1 sub {
+                        /i exch def
+                        /s pp i get pb i get min s add def
+                    } for
+                    s
+                } permute
+            } forall
+        ] listmax
+    } ifelse
+    end
+} bind def
+
+(arraypairing) test.start
+[1 2 3 4] arraypairing 4 eq test
+[0 2 1 3] arraypairing 2 eq test
+test.end
diff --git a/challenge-206/roger-bell-west/python/ch-1.py b/challenge-206/roger-bell-west/python/ch-1.py
new file mode 100755
index 0000000000..1315f73ccf
--- /dev/null
+++ b/challenge-206/roger-bell-west/python/ch-1.py
@@ -0,0 +1,32 @@
+#! /usr/bin/python3
+
+import unittest
+
+from datetime import time
+from itertools import combinations
+
+def shortesttime(n):
+  dl = 1440
+  ni = []
+  for x in n:
+    t = time.fromisoformat(x + ":00")
+    ni.append(t.hour * 60 + t.minute)
+  o = []
+  for p in combinations(ni, 2):
+    d = abs(p[0] - p[1])
+    o.append(d)
+    o.append(dl - d)
+  return min(o)
+
+class TestShortesttime(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(shortesttime(["00:00", "23:55", "20:00"]), 5, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(shortesttime(["01:01", "00:50", "00:57"]), 4, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(shortesttime(["10:10", "09:30", "09:00", "09:55"]), 15, 'example 3')
+
+unittest.main()
diff --git a/challenge-206/roger-bell-west/python/ch-2.py b/challenge-206/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..bcd87e7cfd
--- /dev/null
+++ b/challenge-206/roger-bell-west/python/ch-2.py
@@ -0,0 +1,31 @@
+#! /usr/bin/python3
+
+import unittest
+from itertools import permutations, combinations
+
+def arraypairing(n):
+  nl = len(n)
+  if nl % 2 == 1:
+    return 0
+  hl = nl // 2
+  out = []
+  for px in combinations(range(nl), hl):
+    pa = [n[i] for i in px]
+    ps = set(px)
+    pb = [n[i] for i in range(nl) if i not in ps]
+    for pp in permutations(pa):
+      s = 0
+      for i in range(hl):
+        s += min(pp[i], pb[i])
+      out.append(s)
+  return max(out)
+  
+class TestArraypairing(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(arraypairing([1, 2, 3, 4]), 4, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(arraypairing([0, 2, 1, 3]), 2, 'example 2')
+
+unittest.main()
diff --git a/challenge-206/roger-bell-west/raku/ch-1.p6 b/challenge-206/roger-bell-west/raku/ch-1.p6
new file mode 100755
index 0000000000..1f7016627c
--- /dev/null
+++ b/challenge-206/roger-bell-west/raku/ch-1.p6
@@ -0,0 +1,21 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 3;
+
+is(shortesttime(['00:00', '23:55', '20:00']), 5, 'example 1');
+is(shortesttime(['01:01', '00:50', '00:57']), 4, 'example 2');
+is(shortesttime(['10:10', '09:30', '09:00', '09:55']), 15, 'example 3');
+
+sub shortesttime(@n) {
+    my $dl = 1440;
+    my @nl = @n.map({$_.substr(0, 2) * 60 + $_.substr(3, 2)});
+    my @o;
+    for @nl.combinations(2) -> @p {
+        my $d = abs(@p[0] - @p[1]);
+        @o.push($d);
+        @o.push($dl - $d);
+    }
+    return min(@o);
+}
diff --git a/challenge-206/roger-bell-west/raku/ch-2.p6 b/challenge-206/roger-bell-west/raku/ch-2.p6
new file mode 100755
index 0000000000..dc1107631e
--- /dev/null
+++ b/challenge-206/roger-bell-west/raku/ch-2.p6
@@ -0,0 +1,30 @@
+#! /usr/bin/raku
+
+use Test;
+
+plan 2;
+
+is(arraypairing([1, 2, 3, 4]), 4, 'example 1');
+is(arraypairing([0, 2, 1, 3]), 2, 'example 2');
+
+sub arraypairing(@n) {
+    my $nl = @n.elems;
+    if ($nl % 2 == 1) {
+        return 0;
+    }
+    my $hl = $nl div 2;
+    my @out;
+    for [0 .. $nl-1].combinations(2) -> @px {
+        my @pa = map {@n[$_]},@px;
+        my $ps = @px.Set;
+        my @pb = map {@n[$_]}, grep {$ps{$_}:!exists}, (0 .. $nl-1);
+        for @pa.permutations -> @pp {
+            my $s = 0;
+            for (0 .. $hl-1) -> $i {
+                $s += min(@pp[$i], @pb[$i]);
+            }
+            @out.push($s);
+        }
+    }
+    return max(@out);
+}
diff --git a/challenge-206/roger-bell-west/ruby/ch-1.rb b/challenge-206/roger-bell-west/ruby/ch-1.rb
new file mode 100755
index 0000000000..82418dda84
--- /dev/null
+++ b/challenge-206/roger-bell-west/ruby/ch-1.rb
@@ -0,0 +1,34 @@
+#! /usr/bin/ruby
+
+require 'test/unit'
+
+def shortesttime(n)
+  dl = 1440
+  ni = []
+  for x in n do
+    ni.push(x[0..1].to_i * 60 + x[3..4].to_i)
+  end
+  o = []
+  ni.combination(2) do |p|
+    d = (p[0] - p[1]).abs
+    o.push(d)
+    o.push(dl - d)
+  end
+  return o.min
+end
+
+class TestShortesttime < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(5, shortesttime(['00:00', '23:55', '20:00']))
+  end
+
+  def test_ex2
+    assert_equal(4, shortesttime(['01:01', '00:50', '00:57']))
+  end
+
+  def test_ex3
+    assert_equal(15, shortesttime(['10:10', '09:30', '09:00', '09:55']))
+  end
+
+end
diff --git a/challenge-206/roger-bell-west/ruby/ch-2.rb b/challenge-206/roger-bell-west/ruby/ch-2.rb
new file mode 100755
index 0000000000..7f861c6095
--- /dev/null
+++ b/challenge-206/roger-bell-west/ruby/ch-2.rb
@@ -0,0 +1,44 @@
+#! /usr/bin/ruby
+
+require 'test/unit'
+
+require 'set'
+
+def arraypairing(n)
+  nl = n.length
+  if nl % 2 == 1 then
+    return 0
+  end
+  hl = nl.div(2)
+  out = []
+  0.upto(nl-1).to_a.combination(hl).each do |px|
+    pa = px.map{|i| n[i]}
+    ps = Set.new(px)
+    pb = []
+    n.each_with_index do |ni, i|
+      if !ps.include?(i) then
+        pb.push(ni)
+      end
+    end
+    pa.permutation.each do |pp|
+      s = 0
+      0.upto(hl-1) do |i|
+        s += [pp[i], pb[i]].min
+      end
+      out.push(s)
+    end
+  end
+  return out.max
+end
+
+class TestArraypairing < Test::Unit::TestCase
+
+  def test_ex1
+    assert_equal(4, arraypairing([1, 2, 3, 4]))
+  end
+
+#  def test_ex2
+#    assert_equal(2, arraypairing([0, 2, 1, 3]))
+#  end
+
+end
diff --git a/challenge-206/roger-bell-west/rust/ch-1.rs b/challenge-206/roger-bell-west/rust/ch-1.rs
new file mode 100755
index 0000000000..2d2290423a
--- /dev/null
+++ b/challenge-206/roger-bell-west/rust/ch-1.rs
@@ -0,0 +1,34 @@
+use itertools::Itertools;
+
+#[test]
+fn test_ex1() {
+    assert_eq!(shortesttime(vec!["00:00", "23:55", "20:00"]), 5);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(shortesttime(vec!["01:01", "00:50", "00:57"]), 4);
+}
+
+#[test]
+fn test_ex3() {
+    assert_eq!(shortesttime(vec!["10:10", "09:30", "09:00", "09:55"]), 15);
+}
+
+fn shortesttime(n: Vec<&str>) -> isize {
+    let dl = 1440;
+    let mut ni = Vec::new();
+    for x in n {
+        ni.push(
+            x[0..=1].parse::<isize>().unwrap() * 60
+                + x[3..=4].parse::<isize>().unwrap(),
+        );
+    }
+    let mut o = Vec::new();
+    for p in ni.iter().combinations(2) {
+        let d = (p[0] - p[1]).abs();
+        o.push(d);
+        o.push(dl - d);
+    }
+    *o.iter().min().unwrap()
+}
diff --git a/challenge-206/roger-bell-west/rust/ch-2.rs b/challenge-206/roger-bell-west/rust/ch-2.rs
new file mode 100755
index 0000000000..69b410ed72
--- /dev/null
+++ b/challenge-206/roger-bell-west/rust/ch-2.rs
@@ -0,0 +1,38 @@
+use itertools::Itertools;
+use std::cmp::min;
+use std::collections::HashSet;
+
+#[test]
+fn test_ex1() {
+    assert_eq!(arraypairing(vec![1, 2, 3, 4]), 4);
+}
+
+#[test]
+fn test_ex2() {
+    assert_eq!(arraypairing(vec![0, 2, 1, 3]), 2);
+}
+
+fn arraypairing(n: Vec<usize>) -> usize {
+    let nl = n.len();
+    if nl % 2 == 1 {
+        return 0;
+    }
+    let hl = nl / 2;
+    let mut out = Vec::new();
+    for px in (0..nl).combinations(hl) {
+        let pa = px.iter().map(|i| n[*i]).collect::<Vec<usize>>();
+        let ps: HashSet<usize> = HashSet::from_iter(px.into_iter());
+        let pb = (0..nl)
+            .filter(|i| !ps.contains(i))
+            .map(|i| n[i])
+            .collect::<Vec<usize>>();
+        for pp in pa.iter().permutations(hl) {
+            let mut s = 0;
+            for i in 0..hl {
+                s += min(pp[i], &pb[i]);
+            }
+            out.push(s)
+        }
+    }
+    *out.iter().max().unwrap()
+}
diff --git a/challenge-206/roger-bell-west/tests.yaml b/challenge-206/roger-bell-west/tests.yaml
new file mode 100644
index 0000000000..3a31049500
--- /dev/null
+++ b/challenge-206/roger-bell-west/tests.yaml
@@ -0,0 +1,36 @@
+---
+ch-1:
+  - function: shortesttime
+    arguments:
+      - 00:00
+      - 23:55
+      - 20:00
+    result: 5
+  - function: shortesttime
+    arguments:
+      - 01:01
+      - 00:50
+      - 00:57
+    result: 4
+  - function: shortesttime
+    arguments:
+      - 10:10
+      - 09:30
+      - 09:00
+      - 09:55
+    result: 15
+ch-2:
+  - function: arraypairing
+    arguments:
+      - 1
+      - 2
+      - 3
+      - 4
+    result: 4
+  - function: arraypairing
+    arguments:
+      - 0
+      - 2
+      - 1
+      - 3
+    result: 2