From 134e5e145e559385f24267b98751b870ae28976e Mon Sep 17 00:00:00 2001
From: E7-87-83 <fungcheokyin@gmail.com>
Date: Thu, 28 Oct 2021 18:14:03 +0800
Subject: Week 136 Task 2

---
 challenge-136/cheok-yin-fung/perl/ch-2.pl | 107 ++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 challenge-136/cheok-yin-fung/perl/ch-2.pl

diff --git a/challenge-136/cheok-yin-fung/perl/ch-2.pl b/challenge-136/cheok-yin-fung/perl/ch-2.pl
new file mode 100644
index 0000000000..97b5881380
--- /dev/null
+++ b/challenge-136/cheok-yin-fung/perl/ch-2.pl
@@ -0,0 +1,107 @@
+#!/usr/bin/perl
+# The Weekly Challenge 136
+#  Task 2 Fibonacci Sequence
+#  ( #077 Task 1 Fibonacci Sum )
+# Usage: ch-2.pl $N
+
+# implement http://www-igm.univ-mlv.fr/~berstel/
+#           Articles/2001ExerciceAldo.pdf
+# Author:J. Berstel
+# title: An Exercise on Fibonacci Representations, 
+# RAIRO/Informatique Theorique, Vol. 35, No 6, 2001
+
+# link from https://oeis.org/A000119
+
+use v5.12.0;
+use warnings;
+use Test::More tests => 7;
+use List::Util qw/reduce/;
+
+my $BIGNUM = $ARGV[1] || 102_334_155; # Fib_39 
+my @FIBSEQ = (1, 1);
+generate_up_to_BIGNUM($BIGNUM);
+
+say num_of_fib_repr($ARGV[0]) if defined($ARGV[0]);
+
+
+
+sub num_of_fib_repr {
+    my $num = $_[0];
+    my @zff = zeckendorff_index($num)->@*; 
+    push @zff, 0;
+    my @arr = map {  $zff[$_] - $zff[$_+1] - 1 } 0..$#zff-1;
+    my $matrix = reduce {multi_sq($a,$b)} map {mat($_)} @arr;
+    return $matrix->[0][0] + $matrix->[1][0];
+}
+
+
+
+sub mat {
+    my $d = $_[0];
+    return [ [1, 1], [ int($d/2), int(($d+1)/2) ] ];
+}
+
+
+
+sub multi_sq {
+    my $mat0 = $_[0];
+    my $mat1 = $_[1];
+    return [
+      [
+        $mat0->[0][0] * $mat1->[0][0] + $mat0->[0][1] * $mat1->[1][0], 
+        $mat0->[0][0] * $mat1->[0][1] + $mat0->[0][1] * $mat1->[1][1] 
+      ],
+      [
+        $mat0->[1][0] * $mat1->[0][0] + $mat0->[1][1] * $mat1->[1][0], 
+        $mat0->[1][0] * $mat1->[0][1] + $mat0->[1][1] * $mat1->[1][1] 
+      ]
+    ]
+}
+
+
+
+sub zeckendorff_index {
+    my $num = $_[0];
+    my @arr = ();
+    my $s = get_largest_fib_ind($num);
+    while ($num != 0) {
+        if ($num >= $FIBSEQ[$s]) {
+            $num = $num - $FIBSEQ[$s];
+            push @arr, $s;
+        }
+        $s--;
+    }
+    return [@arr];
+}
+
+
+
+sub get_largest_fib_ind {
+    my $num = $_[0];
+    my $i = 1;
+    while ($num > $FIBSEQ[$i]) {
+        $i++;
+    }
+    return $i;
+}
+
+
+
+sub generate_up_to_BIGNUM {
+    my $r = 1;
+    while ($BIGNUM > $FIBSEQ[$r]) {
+        $FIBSEQ[$r+1] = $FIBSEQ[$r]+$FIBSEQ[$r-1];
+        $r++;
+    }
+}
+
+
+
+
+ok num_of_fib_repr(1) == 1, "test case: N=1";
+ok num_of_fib_repr(2) == 1, "test case: N=2";
+ok num_of_fib_repr(41) == 2, "test case: N=41";
+ok num_of_fib_repr(45) == 6, "test case: N=45";
+ok num_of_fib_repr(54) == 1, "test case: N=54";
+ok num_of_fib_repr(105) == 10, "test case: N=105";
+ok num_of_fib_repr(113) == 10, "test case: N=113";
-- 
cgit