1st commit on 068

3 files changed, 123 insertions, 0 deletions

diff --git a/challenge-068/stuart-little/README b/challenge-068/stuart-little/README
new file mode 100644
index 0000000000..78439907de
--- /dev/null
+++ b/challenge-068/stuart-little/README
@@ -0,0 +1 @@
+Solutions by Stuart Little
diff --git a/challenge-068/stuart-little/raku/ch-1.p6 b/challenge-068/stuart-little/raku/ch-1.p6
new file mode 100755
index 0000000000..d1080b972e
--- /dev/null
+++ b/challenge-068/stuart-little/raku/ch-1.p6
@@ -0,0 +1,18 @@
+#!/usr/bin/env perl6
+use v6;
+
+sub transp(@a) { @a[0].keys.map({ @a[0..*-1;$_] }) }
+sub zero_rows(@a) { @a.map({ ([*] @($_)) xx $_ }).map(*.Array) }
+
+my @a=@*ARGS.map(*.comb.Array);
+for (zip @a.&zero_rows, @a.&transp.&zero_rows.&transp, :with({ @($^a) Z* @($^b) })) {.say}
+
+=finish
+
+Run as <script> <space-separated binary strings>, each binary string representing a row, as in
+
+<script> 101 111 111 to input the matrix
+
+[1, 0, 1]
+[1, 1, 1]
+[1, 1, 1]
diff --git a/challenge-068/stuart-little/raku/ch-2.p6 b/challenge-068/stuart-little/raku/ch-2.p6
new file mode 100755
index 0000000000..cba704d38b
--- /dev/null
+++ b/challenge-068/stuart-little/raku/ch-2.p6
@@ -0,0 +1,104 @@
+#!/usr/bin/env perl6
+use v6;
+
+# run as <script> <space-separated items of the initial list>
+
+class Node is export {
+    has Real $.data;
+    has Node $.next is rw;
+}
+
+class Sll is export {
+    has Node $.head is rw;
+
+    method show() {
+	my $node = self.head;
+	(! $node) && do {say ""; return};
+	while ($node.next) {
+	    print $node.data, " -> ";
+	    $node=$node.next;
+	}
+	say $node.data;	
+    }
+    
+    method len() {
+	my $node = self.head;
+	my $len=0;
+	while ($node) {
+	    $len++;
+	    $node=$node.next;
+	}
+	return $len;	
+    }
+    
+    multi method insert(Real $data) {	
+	my $node=self.head;
+	(! $node) && do {
+	    self.head=Node.new(data => $data);
+	    return;
+	}
+	while ($node.next) {
+	    $node=$node.next;
+	}
+	$node.next=Node.new(data => $data);
+    }
+
+    multi method insert(0, Real $data) {
+	my $node=Node.new(data => $data, next => self.head);
+	self.head=$node;
+    }
+    
+    multi method insert(Int $idx where * > 0, Real $data) {
+	given self.len {
+	    when 0 { self.insert(0,$data) }
+	    when 1..$idx { self.insert($data) }
+	    default {
+		my $cur=self.head;	
+		my $node=Node.new(data => $data);
+		for (0..^($idx-1)) {
+		    $cur=$cur.next;
+		}
+		$node.next=$cur.next;
+		$cur.next=$node;
+	    }
+	}
+    }
+
+    method del(Int $idx where * >= 0) {
+	given $idx {
+	    when self.len..* { warn "Index out of range" }
+	    when 0 { self.head=self.head.next }
+	    default {
+		my $cur=self.head;
+		for (^($idx-1)) {
+		    $cur=$cur.next;
+		}
+		$cur.next=$cur.next.next;
+	    }
+	}
+    }
+}
+
+sub foldback(Sll $ll) {
+    my $len=$ll.len;
+
+    my $curr=$ll.head;
+    for (1..($len div 2)) { $curr = $curr.next }
+    for (1..(($len-1) div 2)) -> $offset {
+	my $data=$curr.next.data;
+	$ll.del(($len div 2)+$offset);
+	$ll.insert((($len-1) div 2)-($offset-1),$data); 
+    }
+    return $ll;
+}
+
+my $ll=Sll.new();
+for (@*ARGS.map(*.Real)) {
+    $ll.insert($_);
+}
+
+print "Initial list: ";
+$ll.show();
+
+print "Folded list: ";
+foldback($ll).show();