Create ch-1.pl

1 files changed, 43 insertions, 0 deletions

diff --git a/challenge-200/james-smith/perl/ch-1.pl b/challenge-200/james-smith/perl/ch-1.pl
new file mode 100644
index 0000000000..5025939f0a
--- /dev/null
+++ b/challenge-200/james-smith/perl/ch-1.pl
@@ -0,0 +1,43 @@
+#!/usr/local/bin/perl
+
+use strict;
+use warnings;
+use feature qw(say);
+use Test::More;
+use Benchmark qw(cmpthese timethis);
+
+my @TESTS = (
+  [ [1..4],    '(1,2,3), (1,2,3,4), (2,3,4)' ],
+  [ [1,3,4,5], '(3,4,5)' ],
+  [ [1,2,3,5,6,7,9,0,-4,-8], '(0,-4,-8), (1,2,3), (5,6,7)' ],
+  [ [1,1,1,1,2,3,4,6,8,10,15,20,25,50,100,125,150,175,200], '(1,1,1), (1,1,1), (1,1,1,1), (1,2,3), (1,2,3,4), (10,15,20), (10,15,20,25), (100,125,150), (100,125,150,175), (100,125,150,175,200), (125,150,175), (125,150,175,200), (15,20,25), (150,175,200), (2,3,4), (4,6,8), (4,6,8,10), (6,8,10)' ],
+  [ [2],    "" ],
+  [ [1,2,4,8,16,32],    "" ],
+);
+is( a_slices( @{$_->[0]}), $_->[1] ) foreach @TESTS;
+done_testing();
+
+## Display an array of arrays compactly...
+sub d_slices { return join ', ', map { '('.join(',', @{$_}).')' } @{$_[0]}; }
+
+
+sub a_slices {
+  ## Less than 1 value return...
+  return unless $#_;
+  ## Set start of sequence to 0, d - the difference between entry 1 and entry 0
+  my($st,$d,@pairs)=(0,$_[1]-$_[0]);
+  ## Loop through all end points
+  for(my$en=1;$en<@_;$en++) {
+    ## If the gap is different - update gap (and start) and continute through loop
+    if($_[$en]-$_[$en-1] != $d) {
+      ($st,$d)=($en-1,$_[$en]-$_[$en-1])
+    ## If it is the same add it and all alternative entries
+    } else {
+      ## We only store the start/end of the runs not the whole sequence
+      push( @pairs, map { [$_,$en] } $st..$en-2 );
+    }
+  }
+  ## Now we find all the start ends and return the series of each of these subsequences.
+  return [ map { [ @_[ $_->[0] .. $_->[1] ] ] } @pairs ];
+}
+