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+Solutions by James Smith.
+
+# Challenge 1 - leader
+
+There are two solutions to this - the naive one works left to right, but the optimal one runs right to left.
+
+```perl
+sub leader {                            ## Most efficient way is to work backwards on this rather 
+                                        ## than forwards...
+
+  return 0 unless @_;                   ## If nothing passed return 0 as requested.
+
+  my @R = my $max = pop @_;             ## Last one will always be a "leader"...
+  foreach ( reverse @_ ) {              ## Work forward and unshift the value if it is now a leader
+    unshift @R, $max = $_ if $max < $_; ## greater than max value (and update max at the same time)
+  }
+
+  return @R;                            ## Return array of leaders...
+}
+```
+
+Notes:
+
+ * This is an O(n) solution where the forward solution is O(n^2);
+
+# Challenge 2 - left rotate
+
+This is a simpler challenge as this is something Perl is even better at - rotating an array is just
+an array slice of the array with the indicies itself rotated...
+
+The index rotation is easy:         "offset" .. "size of list", 0 .. ("offset" - 1);
+
+So the code reduces to:
+
+```perl
+sub rotate {
+  my $a = shift;
+  ## First parameter is an arrayref containing the values to be rotated
+  ## Remaining parameters are the offsets for each rotation
+
+  ## This is a great use of array slicing to achieve what we need
+  ## Indexes go from offset -> size-1 & 0 -> offset-1
+  ## Perl nicely handles the case where the value to the left of
+  ## the double dot is higher than the value to the right
+
+  print "  [@{[ @{$a}[ $_..(@{$a}-1), 0..($_-1) ] ]}]\n" foreach @_;
+
+  ## Let us use the @{[ ]} trick to embed content into the print
+  ## statement - this is a very useful and often under used feature
+  ## of perl which makes for simpler code when rendering output...
+  ## this is nice because print "@A" an print @A are subtly different
+  ## with the "@A" putting spaces (default value of $")
+}
+```
+
+Notes:
+
+ * We use Arrayref slice notation @{ $arrayref }[ @index_list ] to do the rotation
+
+ * We use "@{[ ... ]}" string interpolation to insert these values into the output...