From 2f661f978631af53d9cb473cdef818b8833ca0e9 Mon Sep 17 00:00:00 2001
From: CY Fung <fungcheokyin@gmail.com>
Date: Tue, 7 Jun 2022 20:56:19 +0800
Subject: Week 168 First commit

---
 challenge-168/cheok-yin-fung/perl/ch-1.pl | 33 +++++++++++++++++
 challenge-168/cheok-yin-fung/perl/ch-2.pl | 59 +++++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+)
 create mode 100644 challenge-168/cheok-yin-fung/perl/ch-1.pl
 create mode 100644 challenge-168/cheok-yin-fung/perl/ch-2.pl

(limited to 'challenge-168')

diff --git a/challenge-168/cheok-yin-fung/perl/ch-1.pl b/challenge-168/cheok-yin-fung/perl/ch-1.pl
new file mode 100644
index 0000000000..61ba32d69e
--- /dev/null
+++ b/challenge-168/cheok-yin-fung/perl/ch-1.pl
@@ -0,0 +1,33 @@
+#!/usr/bin/perl
+# The Weekly Challenge 168
+# Task 1 Perrin Prime 
+use v5.24.0;
+use warnings;
+use List::Util qw/reduce none/;
+use Math::BigInt::GMP;          # [remark]
+use Math::BigInt::Pari;         # [remark]
+use Math::Prime::Util::GMP qw/is_prime next_prime/;
+use bigint try => 'GMP,Pari';   # [remark]
+# remark: follow suggestions on POD of Math::Prime::Util
+
+my @perrin_primes = (2,3);
+my ($ppnm3,$ppnm2,$ppnm1, $ppn) = (3,0,2,3);
+
+while (scalar @perrin_primes < 13) {
+    if (is_prime($ppn) == 2) {
+        push @perrin_primes, $ppn if none {$_ == $ppn} @perrin_primes;
+        say $ppn;
+    }
+    $ppnm3 = $ppnm2;
+    $ppnm2 = $ppnm1;
+    $ppnm1 = $ppn;
+    $ppn = $ppnm2 + $ppnm3;
+}
+
+say join ", ", @perrin_primes;
+
+# time: 
+# real	0m0.078s
+# user	0m0.056s
+# sys	0m0.008s
+
diff --git a/challenge-168/cheok-yin-fung/perl/ch-2.pl b/challenge-168/cheok-yin-fung/perl/ch-2.pl
new file mode 100644
index 0000000000..0518d1dbcd
--- /dev/null
+++ b/challenge-168/cheok-yin-fung/perl/ch-2.pl
@@ -0,0 +1,59 @@
+#!/usr/bin/perl
+# The Weekly Challenge 168
+# Task 2 Home Prime 
+# Usage: ch-2.pl [integer > 1]
+use v5.24.0;
+use warnings;
+use List::Util qw/reduce/;
+use Math::BigInt::GMP;          # [remark]
+use Math::BigInt::Pari;         # [remark]
+use Math::Prime::Util::GMP qw/is_prime next_prime/;
+use bigint try => 'GMP,Pari';   # [remark]
+# remark: follow suggestions on POD of Math::Prime::Util
+
+
+say hp($ARGV[0]) if defined($ARGV[0]);
+
+
+
+sub hp {
+    my_hp($_[0],0);
+}
+
+
+
+sub my_hp {
+    my $recur_depth = $_[1];
+
+    die "Walk so far but still cannot get result. :(\n" if $recur_depth > 10;
+    my $num = $_[0];
+    if (is_prime($num) == 2) {
+        return $num;
+    }
+
+    my @factors = ();
+    my $p = 2;
+    do {
+        if (!($num % $p)) {
+            push @factors, $p;
+            $num /= $p;
+        }
+        else {
+            $p = next_prime($p);
+        }
+    } while ($num != 1);
+    my $nxt = (reduce { $a . $b } @factors);
+    say "  $nxt";
+    return my_hp($nxt, ++$recur_depth);
+}
+
+use Test::More tests => 5;
+# test data from OEIS
+ok hp(10) == 773;
+ok hp(24) == 331_319;
+ok hp(32) == 241_271;
+ok hp(45) == 3_411_949;
+
+ok hp(44) == 22815088913;  # this test spends approx 0.5 min (on CY's laptop).
+
+# ok hp(40) == 3314192745739;  # this test spends approx. 2 min.
-- 
cgit 


From 3cc61075c2564e35c4826d6431312e2b0dcf2179 Mon Sep 17 00:00:00 2001
From: CY Fung <fungcheokyin@gmail.com>
Date: Tue, 7 Jun 2022 21:17:33 +0800
Subject: to be improved within this week

---
 challenge-168/cheok-yin-fung/perl/ch-2.pl | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'challenge-168')

diff --git a/challenge-168/cheok-yin-fung/perl/ch-2.pl b/challenge-168/cheok-yin-fung/perl/ch-2.pl
index 0518d1dbcd..3289846cfe 100644
--- a/challenge-168/cheok-yin-fung/perl/ch-2.pl
+++ b/challenge-168/cheok-yin-fung/perl/ch-2.pl
@@ -1,3 +1,5 @@
+# CAN BE IMPROVED
+
 #!/usr/bin/perl
 # The Weekly Challenge 168
 # Task 2 Home Prime 
@@ -39,7 +41,7 @@ sub my_hp {
             $num /= $p;
         }
         else {
-            $p = next_prime($p);
+            $p = next_prime($p);    # CAN BE IMPROVED
         }
     } while ($num != 1);
     my $nxt = (reduce { $a . $b } @factors);
-- 
cgit 


From bf717b19d8279f0a9b908d1f465a821d43f3eb55 Mon Sep 17 00:00:00 2001
From: Stephen Lynn <bizlsg@localhost.localdomain>
Date: Sat, 11 Jun 2022 20:41:39 +0800
Subject: improved raku ch-2

---
 challenge-168/steve-g-lynn/raku/ch-2.p6 | 115 ++++++--------------------------
 1 file changed, 20 insertions(+), 95 deletions(-)

(limited to 'challenge-168')

diff --git a/challenge-168/steve-g-lynn/raku/ch-2.p6 b/challenge-168/steve-g-lynn/raku/ch-2.p6
index bfe46ec923..f3a1259691 100755
--- a/challenge-168/steve-g-lynn/raku/ch-2.p6
+++ b/challenge-168/steve-g-lynn/raku/ch-2.p6
@@ -1,126 +1,51 @@
 #!/usr/bin/raku
 
 #time (bash command): 
-#real	0m0.490s
-#user	0m0.729s
-#sys	0m0.056s
-
-
-# acknowledgement:
-
-# I improved the previous grossly inefficient version 
-# (> 1 min script run time) after looking 
-# at the raku and python submissions from Roger Bell-West
+#real	0m0.511s
+#user	0m0.622s
+#sys	0m0.046s
 
 
 say homeprime(10);
 #773
 say homeprime(16);
 #31636373
+say homeprime(20);
+#3318308475676071413
 
 #-- sub for home prime
 
-sub homeprime(Int $n) returns Int { 
+sub homeprime(Int $n) returns Int {
 	$n.Int.is-prime && return $n;
-	my $ncopy=$n;
-	while (1) {
-		my $last=$ncopy;
-		$ncopy=factor($ncopy);
-		($ncopy==$last) && last;
-	}
-	return $ncopy;
+	return homeprime(factor($n));
 }
 
 #--sub for factorizing
 
-multi sub factor (1) returns Int {1}
-
-multi sub factor (Int $n where $n > 1) returns Int {
+sub factor (Int $n where $n > 1) returns Int {
 #-- returns the concatenated prime factors as an int
 	$n.Int.is-prime && (return $n.Int );
-	my $sqrt_n = sqrt($n).Int+1;
-	my @primes=find_primes($sqrt_n);
+	my Int $sqrt_n = sqrt($n).Int;
+
 	my @factors=();
 
-	my $retstring="";
-	my $ncopy=$n;	
+	my Str $retstring="";
+	my Int $ncopy=$n.Int;	
 	
-	for @primes -> $prime {
-		while ( ($ncopy % $prime)==0) {
-			$ncopy /= $prime;
-			push @factors, $prime;
+	for (2 .. $sqrt_n) -> $prime {
+	#-- no need to generate primes first.. the routine will 
+	#-- automatically only choose prime factors
+		while ($ncopy %% $prime) {
+			$ncopy div= $prime; 	#-- integer division
+			@factors.append($prime);
 		}
+		$ncopy.is-prime && last;
 	}
-	($ncopy > 1) && push @factors, $ncopy;
+	($ncopy > 1) && @factors.append($ncopy);
 	#-- any factor bigger than sqrt(n) is a prime factor
 	$retstring = @factors.list.join;
 
 	return $retstring.Int;
 }
 
-multi sub find_primes(Int $n where $n <= 100) {
-	my @primes=
-	(2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97); 
-	my @retval=();
-	for @primes -> $prime {
-		($prime < $n) && (push @retval, $prime);
-	}
-	return (@retval.sort);
-}
-
-multi sub find_primes (Int $n where $n > 100) {
-	my @primes=[7,11,13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]; #-- candidate primes
-	my %primes{Int}=(); #-- we will return keys of this
-	my $sqrt_n = sqrt($n); #-- ceiling for iterating thru' sieve
-	
-	#-- initialize primes hash
-	#-- store candidates of the form 6k-1 to 6k+1
-	#-- eliminate multiples of known primes
-	loop (my $i=102; $i <= $n+1; $i += 6) {
-		my @temp=($i-1, $i+1);
-		TEMP: for @temp -> $temp {
-			($temp % 3) || next;
-			($temp % 5) || next;
-			for @primes -> $prime {
-				($prime > $sqrt_n) && last;
-				($temp % $prime) || next TEMP;
-			}
-			($temp <= $n) && (%primes{$temp}=True);
-		}
-	}
-		
-	#-- for prime candidates k greater than @primes[*-1]
-	#-- use odd numbers not divisible by 3 (last value + 4 and +6 if
-	#   we start counting from 97)
-	#-- loop through factors kk+jk < n and delete
-	#-- any %hash entries with key matching these factors.
-
-	my $last_prime = @primes[*-1];
-	if ($last_prime < $sqrt_n) { 
-		@primes=[$last_prime+4, $last_prime+2];
-		while (1) {
-			my $prime = shift @primes;
-			(@primes.elems==0) && 
-				(@primes.append($prime+4, $prime+2));
-			#-- avoid multiples of 3
-			
-			last if $prime > $sqrt_n;
-		
-			#-- only loop if the candidate is in the primes hash
-			if  ( %primes{$prime} ) {
-				loop (my $i=$prime*$prime; 
-					$i <= $n;
-					$i += $prime) {
-						%primes{$i}:delete;
-				}
-			}
-		}
-	}
-	my @retval=(2,3,5,7,11,13,17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97);
-	return (@retval.append(%primes.keys.sort));
-
-	return 1;
-}
-
-
 
-- 
cgit 


From 3d271507b2ad90a357fb128df8fcf47b66f91ffb Mon Sep 17 00:00:00 2001
From: Stephen Lynn <bizlsg@localhost.localdomain>
Date: Sat, 11 Jun 2022 21:03:20 +0800
Subject: improved perl ch-2.pl

---
 challenge-168/steve-g-lynn/perl/ch-2.pl | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

(limited to 'challenge-168')

diff --git a/challenge-168/steve-g-lynn/perl/ch-2.pl b/challenge-168/steve-g-lynn/perl/ch-2.pl
index d1f6f0aced..4732c9b136 100755
--- a/challenge-168/steve-g-lynn/perl/ch-2.pl
+++ b/challenge-168/steve-g-lynn/perl/ch-2.pl
@@ -1,13 +1,17 @@
 #!/usr/bin/perl
 
-use Math::Prime::XS qw(is_prime sieve_primes);
-
+use Math::Prime::XS qw(is_prime);
 
+print &home_prime(10),"\n";
+#773
 print &home_prime(16),"\n";
-#-- should be 31636373 [wikipedia example]
+#31636373
+print &home_prime(20),"\n";
+#3318308475676071413
 
 sub home_prime {
-	local ($n)=@_;
+	my ($n)=@_;
+	is_prime($n) && return $n;
 	while (1){
 		$n=&factors($n);
 		(is_prime($n)) && last;
@@ -18,20 +22,25 @@ sub home_prime {
 
 sub factors {
 	#--return concatenated prime factors of a number n 
-	local ($n)=@_;
-	local @primes=sieve_primes($n);
-	local $retstring="";
+	my ($n)=@_;
+	local $sqrt_n=int(sqrt($n));
+
+	my $retstring="";
 	
 	if (is_prime($n)){
 		return $n;
 	}
 	else {
-		foreach $prime (sort{$a<=>$b} @primes){
+		for $prime (2 .. $sqrt_n){
+		#-- no need to get primes first
+		#-- routine automatically finds only prime factors
 			while ( ($n % $prime) == 0){
 				$n /= $prime;
 				$retstring .= $prime;
 			}
+			(is_prime($n)) && last; 
 		}
+		($n > 1) && ($retstring .= $n);
 	}
 	return $retstring;	
 }
-- 
cgit 


From 5182b192585848d1b91afce11d151906762d9bcd Mon Sep 17 00:00:00 2001
From: Stephen Lynn <bizlsg@localhost.localdomain>
Date: Sat, 11 Jun 2022 21:07:19 +0800
Subject: improved ch-2.pl

---
 challenge-168/steve-g-lynn/perl/ch-2.pl | 1 +
 1 file changed, 1 insertion(+)

(limited to 'challenge-168')

diff --git a/challenge-168/steve-g-lynn/perl/ch-2.pl b/challenge-168/steve-g-lynn/perl/ch-2.pl
index 4732c9b136..4fcc0e19dd 100755
--- a/challenge-168/steve-g-lynn/perl/ch-2.pl
+++ b/challenge-168/steve-g-lynn/perl/ch-2.pl
@@ -9,6 +9,7 @@ print &home_prime(16),"\n";
 print &home_prime(20),"\n";
 #3318308475676071413
 
+
 sub home_prime {
 	my ($n)=@_;
 	is_prime($n) && return $n;
-- 
cgit 


From 337a373ae28cb51b8d74be6505b2f695e5ac2cb5 Mon Sep 17 00:00:00 2001
From: Stephen Lynn <bizlsg@localhost.localdomain>
Date: Sat, 11 Jun 2022 21:10:58 +0800
Subject: improved perl ch-2.pl

---
 challenge-168/steve-g-lynn/perl/ch-2.pl | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'challenge-168')

diff --git a/challenge-168/steve-g-lynn/perl/ch-2.pl b/challenge-168/steve-g-lynn/perl/ch-2.pl
index 4fcc0e19dd..67db0846ea 100755
--- a/challenge-168/steve-g-lynn/perl/ch-2.pl
+++ b/challenge-168/steve-g-lynn/perl/ch-2.pl
@@ -10,6 +10,7 @@ print &home_prime(20),"\n";
 #3318308475676071413
 
 
+
 sub home_prime {
 	my ($n)=@_;
 	is_prime($n) && return $n;
@@ -21,6 +22,7 @@ sub home_prime {
 }
 
 
+
 sub factors {
 	#--return concatenated prime factors of a number n 
 	my ($n)=@_;
-- 
cgit 


From ff980517b9e50ee68b469cddc0ca26e5f9982cee Mon Sep 17 00:00:00 2001
From: Stephen Lynn <bizlsg@localhost.localdomain>
Date: Sat, 11 Jun 2022 21:20:08 +0800
Subject: improved ch-2.pl

---
 challenge-168/steve-g-lynn/perl/ch-2.pl | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

(limited to 'challenge-168')

diff --git a/challenge-168/steve-g-lynn/perl/ch-2.pl b/challenge-168/steve-g-lynn/perl/ch-2.pl
index 67db0846ea..be079624bc 100755
--- a/challenge-168/steve-g-lynn/perl/ch-2.pl
+++ b/challenge-168/steve-g-lynn/perl/ch-2.pl
@@ -9,8 +9,6 @@ print &home_prime(16),"\n";
 print &home_prime(20),"\n";
 #3318308475676071413
 
-
-
 sub home_prime {
 	my ($n)=@_;
 	is_prime($n) && return $n;
@@ -21,12 +19,10 @@ sub home_prime {
 	return $n;
 }
 
-
-
 sub factors {
 	#--return concatenated prime factors of a number n 
 	my ($n)=@_;
-	local $sqrt_n=int(sqrt($n));
+	local $sqrt_n=floor(sqrt($n));
 
 	my $retstring="";
 	
-- 
cgit 


From bfba759aa6812adf1536870315cc6648b97163c5 Mon Sep 17 00:00:00 2001
From: Stephen Lynn <bizlsg@localhost.localdomain>
Date: Sat, 11 Jun 2022 21:45:00 +0800
Subject: improved ch-2.pl

---
 challenge-168/steve-g-lynn/perl/ch-2.pl | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'challenge-168')

diff --git a/challenge-168/steve-g-lynn/perl/ch-2.pl b/challenge-168/steve-g-lynn/perl/ch-2.pl
index be079624bc..5fe95544ad 100755
--- a/challenge-168/steve-g-lynn/perl/ch-2.pl
+++ b/challenge-168/steve-g-lynn/perl/ch-2.pl
@@ -4,8 +4,10 @@ use Math::Prime::XS qw(is_prime);
 
 print &home_prime(10),"\n";
 #773
+
 print &home_prime(16),"\n";
 #31636373
+
 print &home_prime(20),"\n";
 #3318308475676071413
 
@@ -43,3 +45,6 @@ sub factors {
 	}
 	return $retstring;	
 }
+
+1;
+
-- 
cgit 


From fbe67d4a7029265af7d2e0a7ff6bd642bc748105 Mon Sep 17 00:00:00 2001
From: Lubos Kolouch <lubos@kolouch.net>
Date: Sat, 11 Jun 2022 19:03:46 +0200
Subject: feat(challenge-168/lubos-kolouch/p[erl,ython]/ch-2.p[ly]): Challenge
 168 Task 2 LK Perl Python

---
 challenge-168/lubos-kolouch/perl/ch-2.pl   | 24 ++++++++++++++++++++++++
 challenge-168/lubos-kolouch/python/ch-2.py | 19 +++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 challenge-168/lubos-kolouch/perl/ch-2.pl
 create mode 100644 challenge-168/lubos-kolouch/python/ch-2.py

(limited to 'challenge-168')

diff --git a/challenge-168/lubos-kolouch/perl/ch-2.pl b/challenge-168/lubos-kolouch/perl/ch-2.pl
new file mode 100644
index 0000000000..1390fba896
--- /dev/null
+++ b/challenge-168/lubos-kolouch/perl/ch-2.pl
@@ -0,0 +1,24 @@
+use strict;
+use warnings;
+use Math::Prime::Util qw/is_prime factor/;
+
+sub home_prime {
+    my $n = shift;
+
+    while ( !is_prime($n) ) {
+        my @factors = factor($n);
+        my $sum     = '';
+        foreach my $factor (@factors) {
+            $sum .= $factor;
+        }
+        $n = $sum;
+    }
+
+    return $n;
+}
+
+use Test::More;
+
+is( home_prime(2),  2 );
+is( home_prime(10), 773 );
+done_testing;
diff --git a/challenge-168/lubos-kolouch/python/ch-2.py b/challenge-168/lubos-kolouch/python/ch-2.py
new file mode 100644
index 0000000000..16094e836d
--- /dev/null
+++ b/challenge-168/lubos-kolouch/python/ch-2.py
@@ -0,0 +1,19 @@
+from sympy import factorint, isprime
+
+
+def home_prime(n):
+
+    while not isprime(n):
+        factors = factorint(n)
+
+        my_sum = ""
+        for (my_factor, repetition) in factors.items():
+            my_sum += str(my_factor) * repetition
+
+        n = int(my_sum)
+
+    return n
+
+
+assert home_prime(2) == 2
+assert home_prime(10) == 773
-- 
cgit 


From ca71189e5959ea925a05c5b4412a64e5d10efe96 Mon Sep 17 00:00:00 2001
From: CY Fung <fungcheokyin@gmail.com>
Date: Sun, 12 Jun 2022 05:00:23 +0800
Subject: improve efficiency

---
 challenge-168/cheok-yin-fung/perl/ch-2.pl | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

(limited to 'challenge-168')

diff --git a/challenge-168/cheok-yin-fung/perl/ch-2.pl b/challenge-168/cheok-yin-fung/perl/ch-2.pl
index 3289846cfe..7466f52b01 100644
--- a/challenge-168/cheok-yin-fung/perl/ch-2.pl
+++ b/challenge-168/cheok-yin-fung/perl/ch-2.pl
@@ -27,7 +27,7 @@ sub hp {
 sub my_hp {
     my $recur_depth = $_[1];
 
-    die "Walk so far but still cannot get result. :(\n" if $recur_depth > 10;
+    die "Walk so far but still cannot get result. :(\n" if $recur_depth > 20;
     my $num = $_[0];
     if (is_prime($num) == 2) {
         return $num;
@@ -35,27 +35,35 @@ sub my_hp {
 
     my @factors = ();
     my $p = 2;
-    do {
+    while ($num != 1) {
         if (!($num % $p)) {
             push @factors, $p;
             $num /= $p;
         }
         else {
-            $p = next_prime($p);    # CAN BE IMPROVED
+            $p = next_prime($p);
         }
-    } while ($num != 1);
+        if ($p > sqrt $num) {
+            push @factors, $num;
+            last;
+        }
+    }
     my $nxt = (reduce { $a . $b } @factors);
     say "  $nxt";
     return my_hp($nxt, ++$recur_depth);
 }
 
-use Test::More tests => 5;
+use Test::More tests => 7;
 # test data from OEIS
 ok hp(10) == 773;
 ok hp(24) == 331_319;
 ok hp(32) == 241_271;
+ok hp(40) == 3314192745739;  
+ok hp(44) == 22815088913;  
 ok hp(45) == 3_411_949;
+ok hp(8) == 3331113965338635107;
 
-ok hp(44) == 22815088913;  # this test spends approx 0.5 min (on CY's laptop).
-
-# ok hp(40) == 3314192745739;  # this test spends approx. 2 min.
+# time:
+# real	0m1.963s
+# user	0m1.946s
+# sys	0m0.016s
-- 
cgit 


From eb043eb2670bd851f4f237961dc12036927fc570 Mon Sep 17 00:00:00 2001
From: CY Fung <fungcheokyin@gmail.com>
Date: Sun, 12 Jun 2022 05:42:04 +0800
Subject: failed attempt: is_prime(BigInt) does not work

---
 challenge-168/cheok-yin-fung/perl/ch-2.pl | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

(limited to 'challenge-168')

diff --git a/challenge-168/cheok-yin-fung/perl/ch-2.pl b/challenge-168/cheok-yin-fung/perl/ch-2.pl
index 7466f52b01..0f08ab3dc4 100644
--- a/challenge-168/cheok-yin-fung/perl/ch-2.pl
+++ b/challenge-168/cheok-yin-fung/perl/ch-2.pl
@@ -28,7 +28,7 @@ sub my_hp {
     my $recur_depth = $_[1];
 
     die "Walk so far but still cannot get result. :(\n" if $recur_depth > 20;
-    my $num = $_[0];
+    my $num = Math::BigInt->new($_[0]);
     if (is_prime($num) == 2) {
         return $num;
     }
@@ -36,24 +36,28 @@ sub my_hp {
     my @factors = ();
     my $p = 2;
     while ($num != 1) {
-        if (!($num % $p)) {
+        my $temp_num = $num;
+        if ( $num->bmod($p) == 0 ) {
+            say $p;
             push @factors, $p;
-            $num /= $p;
+            $num = $num->bdiv($p);
         }
         else {
             $p = next_prime($p);
         }
-        if ($p > sqrt $num) {
+        if ($p > $temp_num->bsqrt()) {
             push @factors, $num;
             last;
         }
     }
-    my $nxt = (reduce { $a . $b } @factors);
+    my $nxt = join "", @factors;
     say "  $nxt";
     return my_hp($nxt, ++$recur_depth);
 }
 
-use Test::More tests => 7;
+
+=pod
+use Test::More tests => 8;
 # test data from OEIS
 ok hp(10) == 773;
 ok hp(24) == 331_319;
@@ -61,9 +65,16 @@ ok hp(32) == 241_271;
 ok hp(40) == 3314192745739;  
 ok hp(44) == 22815088913;  
 ok hp(45) == 3_411_949;
-ok hp(8) == 3331113965338635107;
+ok hp( 8) == 3331113965338635107;
+ok hp(48) == 6161791591356884791277;
 
-# time:
+# time without the last hp(48) test case:
 # real	0m1.963s
 # user	0m1.946s
 # sys	0m0.016s
+#
+# time without the last hp(48) test case and use simply Math::Prime::Util :
+# real	0m0.133s
+# user	0m0.115s
+# sys	0m0.011s
+
-- 
cgit 


From f95f9de8bebf4967125de3a10999cbe524f9f1a3 Mon Sep 17 00:00:00 2001
From: Dave Jacoby <jacoby.david@gmail.com>
Date: Sat, 11 Jun 2022 18:02:10 -0400
Subject: Forgot to finish

---
 challenge-168/dave-jacoby/blog.txt     |  3 +++
 challenge-168/dave-jacoby/perl/ch-1.pl | 28 +++++++++++++++++++
 challenge-168/dave-jacoby/perl/ch-2.pl | 49 ++++++++++++++++++++++++++++++++++
 3 files changed, 80 insertions(+)
 create mode 100644 challenge-168/dave-jacoby/blog.txt
 create mode 100644 challenge-168/dave-jacoby/perl/ch-1.pl
 create mode 100644 challenge-168/dave-jacoby/perl/ch-2.pl

(limited to 'challenge-168')

diff --git a/challenge-168/dave-jacoby/blog.txt b/challenge-168/dave-jacoby/blog.txt
new file mode 100644
index 0000000000..b28b04f643
--- /dev/null
+++ b/challenge-168/dave-jacoby/blog.txt
@@ -0,0 +1,3 @@
+
+
+
diff --git a/challenge-168/dave-jacoby/perl/ch-1.pl b/challenge-168/dave-jacoby/perl/ch-1.pl
new file mode 100644
index 0000000000..39a1510b86
--- /dev/null
+++ b/challenge-168/dave-jacoby/perl/ch-1.pl
@@ -0,0 +1,28 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say postderef signatures state };
+
+my @perrin = ( 3, 0, 2 );
+my %perrin_primes;
+$perrin_primes{2} = 1;
+$perrin_primes{3} = 1;
+
+while ( scalar keys %perrin_primes < 13 ) {
+    my $x = $perrin[-2] + $perrin[-3];
+    push @perrin, $x;
+    $perrin_primes{$x} = 1 if is_prime($x);
+}
+
+say join ' ', sort { $a <=> $b } keys %perrin_primes;
+exit;
+
+sub is_prime ($n) {
+    die "Bad number $n" unless length $n;
+    return 0 if $n == 0;
+    return 0 if $n == 1;
+    for ( 2 .. sqrt $n ) { return 0 unless $n % $_ }
+    return 1;
+}
+
diff --git a/challenge-168/dave-jacoby/perl/ch-2.pl b/challenge-168/dave-jacoby/perl/ch-2.pl
new file mode 100644
index 0000000000..1d101a36a4
--- /dev/null
+++ b/challenge-168/dave-jacoby/perl/ch-2.pl
@@ -0,0 +1,49 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say postderef signatures state };
+
+use Carp;
+use Try::Tiny;
+use Math::Prime::XS qw{ is_prime };
+
+$| = 1;
+
+my @n = @ARGV;
+push @n, 10 unless scalar @ARGV;
+
+for my $i (@n) {
+    try {
+        my $p = get_home_prime($i);
+        say join "\t", '-', $i, $p;
+    }
+    catch {
+        say $_;
+    };
+}
+
+sub get_home_prime($n) {
+    my $p = $n;
+    while ( !is_prime($p) ) {
+        my @factors = get_factors($p);
+        $p = join '', @factors;
+        print qq{$p };
+        # croak 'Too Big, Too Slow' if length $p > 10;
+    }
+    say '';
+    return $p;
+}
+
+sub get_factors( $n ) {
+    my @factors;
+    for my $i ( 2 .. $n ) {
+        next unless $n % $i == 0;
+        while ( $n % $i == 0 ) {
+            push @factors, $i;
+            $n = $n / $i;
+        }
+    }
+    return @factors;
+}
+
-- 
cgit 


From 87a49e0dde51ea6a342eaecef8820bf0b3bc5ead Mon Sep 17 00:00:00 2001
From: CY Fung <fungcheokyin@gmail.com>
Date: Sun, 12 Jun 2022 06:10:22 +0800
Subject: finalize Task 1

---
 challenge-168/cheok-yin-fung/perl/ch-2.pl | 46 +++++++++++++------------------
 1 file changed, 19 insertions(+), 27 deletions(-)

(limited to 'challenge-168')

diff --git a/challenge-168/cheok-yin-fung/perl/ch-2.pl b/challenge-168/cheok-yin-fung/perl/ch-2.pl
index 0f08ab3dc4..3e16406fbd 100644
--- a/challenge-168/cheok-yin-fung/perl/ch-2.pl
+++ b/challenge-168/cheok-yin-fung/perl/ch-2.pl
@@ -1,5 +1,3 @@
-# CAN BE IMPROVED
-
 #!/usr/bin/perl
 # The Weekly Challenge 168
 # Task 2 Home Prime 
@@ -7,14 +5,10 @@
 use v5.24.0;
 use warnings;
 use List::Util qw/reduce/;
-use Math::BigInt::GMP;          # [remark]
-use Math::BigInt::Pari;         # [remark]
-use Math::Prime::Util::GMP qw/is_prime next_prime/;
-use bigint try => 'GMP,Pari';   # [remark]
-# remark: follow suggestions on POD of Math::Prime::Util
-
+use Math::Prime::Util qw/is_prime next_prime/;
+use Math::BigInt;
 
-say hp($ARGV[0]) if defined($ARGV[0]);
+say hp($ARGV[0]) if defined($ARGV[0]) && $ARGV[0] != 1;
 
 
 
@@ -27,8 +21,14 @@ sub hp {
 sub my_hp {
     my $recur_depth = $_[1];
 
+    die "Number involed too large.\n" 
+        if  
+            Math::BigInt->new(18446744073709551616) # 2**64
+                        ->bcmp( Math::BigInt->new($_[0]) )
+              == -1;
+
     die "Walk so far but still cannot get result. :(\n" if $recur_depth > 20;
-    my $num = Math::BigInt->new($_[0]);
+    my $num = $_[0];
     if (is_prime($num) == 2) {
         return $num;
     }
@@ -36,27 +36,23 @@ sub my_hp {
     my @factors = ();
     my $p = 2;
     while ($num != 1) {
-        my $temp_num = $num;
-        if ( $num->bmod($p) == 0 ) {
-            say $p;
+        if (!($num % $p)) {
             push @factors, $p;
-            $num = $num->bdiv($p);
+            $num /= $p;
         }
         else {
             $p = next_prime($p);
         }
-        if ($p > $temp_num->bsqrt()) {
+        if ($p > sqrt $num) {
             push @factors, $num;
             last;
         }
     }
-    my $nxt = join "", @factors;
+    my $nxt = (reduce { $a . $b } @factors);
     say "  $nxt";
     return my_hp($nxt, ++$recur_depth);
 }
 
-
-=pod
 use Test::More tests => 8;
 # test data from OEIS
 ok hp(10) == 773;
@@ -65,16 +61,12 @@ ok hp(32) == 241_271;
 ok hp(40) == 3314192745739;  
 ok hp(44) == 22815088913;  
 ok hp(45) == 3_411_949;
+
+# bigger cases;
 ok hp( 8) == 3331113965338635107;
-ok hp(48) == 6161791591356884791277;
+ok hp(20) == 3318308475676071413;
 
-# time without the last hp(48) test case:
-# real	0m1.963s
-# user	0m1.946s
+# real	0m5.553s
+# user	0m5.535s
 # sys	0m0.016s
-#
-# time without the last hp(48) test case and use simply Math::Prime::Util :
-# real	0m0.133s
-# user	0m0.115s
-# sys	0m0.011s
 
-- 
cgit 


From a2d9f56f20f4773112b0656892fd4a0945fbe401 Mon Sep 17 00:00:00 2001
From: CY Fung <fungcheokyin@gmail.com>
Date: Sun, 12 Jun 2022 06:10:58 +0800
Subject: finalize Task 2

---
 challenge-168/cheok-yin-fung/perl/ch-2.pl | 1 -
 1 file changed, 1 deletion(-)

(limited to 'challenge-168')

diff --git a/challenge-168/cheok-yin-fung/perl/ch-2.pl b/challenge-168/cheok-yin-fung/perl/ch-2.pl
index 3e16406fbd..ea156c4976 100644
--- a/challenge-168/cheok-yin-fung/perl/ch-2.pl
+++ b/challenge-168/cheok-yin-fung/perl/ch-2.pl
@@ -4,7 +4,6 @@
 # Usage: ch-2.pl [integer > 1]
 use v5.24.0;
 use warnings;
-use List::Util qw/reduce/;
 use Math::Prime::Util qw/is_prime next_prime/;
 use Math::BigInt;
 
-- 
cgit 


From 7860753cd854ea07a29511477a5e4a3dca5a885e Mon Sep 17 00:00:00 2001
From: Mohammad S Anwar <mohammad.anwar@yahoo.com>
Date: Sat, 11 Jun 2022 23:34:50 +0100
Subject: - Added solutions by Laurent Rosenfeld.

---
 challenge-168/laurent-rosenfeld/blog.txt       |  1 +
 challenge-168/laurent-rosenfeld/perl/ch-1.pl   | 33 ++++++++++++++++++++++++++
 challenge-168/laurent-rosenfeld/raku/ch-1.raku |  1 +
 3 files changed, 35 insertions(+)
 create mode 100644 challenge-168/laurent-rosenfeld/blog.txt
 create mode 100644 challenge-168/laurent-rosenfeld/perl/ch-1.pl
 create mode 100644 challenge-168/laurent-rosenfeld/raku/ch-1.raku

(limited to 'challenge-168')

diff --git a/challenge-168/laurent-rosenfeld/blog.txt b/challenge-168/laurent-rosenfeld/blog.txt
new file mode 100644
index 0000000000..388761ba75
--- /dev/null
+++ b/challenge-168/laurent-rosenfeld/blog.txt
@@ -0,0 +1 @@
+http://blogs.perl.org/users/laurent_r/2022/06/perl-weekly-challenge-168-perrin-primes.html
diff --git a/challenge-168/laurent-rosenfeld/perl/ch-1.pl b/challenge-168/laurent-rosenfeld/perl/ch-1.pl
new file mode 100644
index 0000000000..906b341080
--- /dev/null
+++ b/challenge-168/laurent-rosenfeld/perl/ch-1.pl
@@ -0,0 +1,33 @@
+use strict;
+use warnings;
+use feature "say";
+
+my @perrin = (3, 0, 2);
+my @result = (2, 3);
+my %seen = map { $_ => 1 } @result;
+while (1) {
+    my $new_item = $perrin[-3] + $perrin[-2];
+    push @perrin, $new_item;
+    if (is_prime($new_item)) {
+        push @result, $new_item unless $seen{$new_item};
+        $seen{$new_item} = 1;
+        last if @result > 12;
+    }
+}
+say join " ", sort { $a <=> $b } @result;
+
+sub is_prime {
+   my $n = shift;
+   return 1 if $n == 2;
+   return 0 if $n % 2 == 0;
+   return 0 if $n == 1;
+
+   my $p = 3;
+   my $sqrt = sqrt $n;
+   while ($p <= $sqrt) {
+       # return 1 if $p >= $n;
+       return 0 if $n % $p == 0;
+       $p += 2;
+   }
+   return 1;
+}
diff --git a/challenge-168/laurent-rosenfeld/raku/ch-1.raku b/challenge-168/laurent-rosenfeld/raku/ch-1.raku
new file mode 100644
index 0000000000..f00ae2d3ef
--- /dev/null
+++ b/challenge-168/laurent-rosenfeld/raku/ch-1.raku
@@ -0,0 +1 @@
+say (unique grep {.is-prime}, (3, 0, 2, -> $a, $b, $c { $a + $b } ... ∞))[0..12].sort;
-- 
cgit 


From 8a6b17c38547a2663b7a46e51dc8fc07c1201889 Mon Sep 17 00:00:00 2001
From: Stephen Lynn <bizlsg@localhost.localdomain>
Date: Sun, 12 Jun 2022 11:21:46 +0800
Subject: faster ch-2.pl & ch-2.p6 using external libs

---
 challenge-168/steve-g-lynn/perl/ch-2.pl | 37 ++++++------------------------
 challenge-168/steve-g-lynn/raku/ch-2.p6 | 40 ++++++---------------------------
 2 files changed, 14 insertions(+), 63 deletions(-)

(limited to 'challenge-168')

diff --git a/challenge-168/steve-g-lynn/perl/ch-2.pl b/challenge-168/steve-g-lynn/perl/ch-2.pl
index 5fe95544ad..379ffd9078 100755
--- a/challenge-168/steve-g-lynn/perl/ch-2.pl
+++ b/challenge-168/steve-g-lynn/perl/ch-2.pl
@@ -1,6 +1,11 @@
 #!/usr/bin/perl
 
-use Math::Prime::XS qw(is_prime);
+#time (bash) output:
+#real	0m0.026s
+#user	0m0.019s
+#sys	0m0.007s
+
+use Math::Prime::Util qw(is_prime factor);
 
 print &home_prime(10),"\n";
 #773
@@ -14,37 +19,9 @@ print &home_prime(20),"\n";
 sub home_prime {
 	my ($n)=@_;
 	is_prime($n) && return $n;
-	while (1){
-		$n=&factors($n);
-		(is_prime($n)) && last;
-	}
-	return $n;
+	return	&home_prime(join('',sort{$a<=>$b}(factor($n))));
 }
 
-sub factors {
-	#--return concatenated prime factors of a number n 
-	my ($n)=@_;
-	local $sqrt_n=floor(sqrt($n));
-
-	my $retstring="";
-	
-	if (is_prime($n)){
-		return $n;
-	}
-	else {
-		for $prime (2 .. $sqrt_n){
-		#-- no need to get primes first
-		#-- routine automatically finds only prime factors
-			while ( ($n % $prime) == 0){
-				$n /= $prime;
-				$retstring .= $prime;
-			}
-			(is_prime($n)) && last; 
-		}
-		($n > 1) && ($retstring .= $n);
-	}
-	return $retstring;	
-}
 
 1;
 
diff --git a/challenge-168/steve-g-lynn/raku/ch-2.p6 b/challenge-168/steve-g-lynn/raku/ch-2.p6
index f3a1259691..869bc8b3b5 100755
--- a/challenge-168/steve-g-lynn/raku/ch-2.p6
+++ b/challenge-168/steve-g-lynn/raku/ch-2.p6
@@ -1,11 +1,13 @@
 #!/usr/bin/raku
 
 #time (bash command): 
-#real	0m0.511s
-#user	0m0.622s
-#sys	0m0.046s
+#real	0m0.312s
+#user	0m0.382s
+#sys	0m0.054s
 
 
+use Prime::Factor;
+
 say homeprime(10);
 #773
 say homeprime(16);
@@ -15,37 +17,9 @@ say homeprime(20);
 
 #-- sub for home prime
 
-sub homeprime(Int $n) returns Int {
+sub homeprime(Int $n where ($n > 1)) returns Int {
 	$n.Int.is-prime && return $n;
-	return homeprime(factor($n));
-}
-
-#--sub for factorizing
-
-sub factor (Int $n where $n > 1) returns Int {
-#-- returns the concatenated prime factors as an int
-	$n.Int.is-prime && (return $n.Int );
-	my Int $sqrt_n = sqrt($n).Int;
-
-	my @factors=();
-
-	my Str $retstring="";
-	my Int $ncopy=$n.Int;	
-	
-	for (2 .. $sqrt_n) -> $prime {
-	#-- no need to generate primes first.. the routine will 
-	#-- automatically only choose prime factors
-		while ($ncopy %% $prime) {
-			$ncopy div= $prime; 	#-- integer division
-			@factors.append($prime);
-		}
-		$ncopy.is-prime && last;
-	}
-	($ncopy > 1) && @factors.append($ncopy);
-	#-- any factor bigger than sqrt(n) is a prime factor
-	$retstring = @factors.list.join;
-
-	return $retstring.Int;
+	return homeprime(([~] prime-factors($n)).Int);
 }
 
 
-- 
cgit 


From 625339f89da8024a9de690f5ed163839989fa40a Mon Sep 17 00:00:00 2001
From: CY Fung <fungcheokyin@gmail.com>
Date: Sun, 12 Jun 2022 11:26:01 +0800
Subject: Task 2 big num

---
 challenge-168/cheok-yin-fung/perl/ch-2.pl | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

(limited to 'challenge-168')

diff --git a/challenge-168/cheok-yin-fung/perl/ch-2.pl b/challenge-168/cheok-yin-fung/perl/ch-2.pl
index ea156c4976..6986c4809a 100644
--- a/challenge-168/cheok-yin-fung/perl/ch-2.pl
+++ b/challenge-168/cheok-yin-fung/perl/ch-2.pl
@@ -18,20 +18,20 @@ sub hp {
 
 
 sub my_hp {
+    my $num = $_[0];
     my $recur_depth = $_[1];
-
-    die "Number involed too large.\n" 
+    die "Number involved too large.\n" 
         if  
-            Math::BigInt->new(18446744073709551616) # 2**64
-                        ->bcmp( Math::BigInt->new($_[0]) )
-              == -1;
+            Math::BigInt->new("18446744073709551616") # 2**64
+                        ->ble( Math::BigInt->new($num) );
+    
 
-    die "Walk so far but still cannot get result. :(\n" if $recur_depth > 20;
-    my $num = $_[0];
     if (is_prime($num) == 2) {
         return $num;
     }
 
+    die "Walk so far but still cannot get result. :(\n" if $recur_depth > 20;
+
     my @factors = ();
     my $p = 2;
     while ($num != 1) {
@@ -47,7 +47,7 @@ sub my_hp {
             last;
         }
     }
-    my $nxt = (reduce { $a . $b } @factors);
+    my $nxt = join "", @factors;
     say "  $nxt";
     return my_hp($nxt, ++$recur_depth);
 }
-- 
cgit 


From 0d0f645575dc2177e765b1e4b64806f591663199 Mon Sep 17 00:00:00 2001
From: CY Fung <fungcheokyin@gmail.com>
Date: Sun, 12 Jun 2022 11:33:20 +0800
Subject: Task 1 final

---
 challenge-168/cheok-yin-fung/perl/ch-1.pl | 14 +++++---------
 challenge-168/cheok-yin-fung/perl/ch-2.pl |  1 +
 2 files changed, 6 insertions(+), 9 deletions(-)

(limited to 'challenge-168')

diff --git a/challenge-168/cheok-yin-fung/perl/ch-1.pl b/challenge-168/cheok-yin-fung/perl/ch-1.pl
index 61ba32d69e..3f51cb4766 100644
--- a/challenge-168/cheok-yin-fung/perl/ch-1.pl
+++ b/challenge-168/cheok-yin-fung/perl/ch-1.pl
@@ -3,12 +3,8 @@
 # Task 1 Perrin Prime 
 use v5.24.0;
 use warnings;
-use List::Util qw/reduce none/;
-use Math::BigInt::GMP;          # [remark]
-use Math::BigInt::Pari;         # [remark]
-use Math::Prime::Util::GMP qw/is_prime next_prime/;
-use bigint try => 'GMP,Pari';   # [remark]
-# remark: follow suggestions on POD of Math::Prime::Util
+use List::Util qw/none/;
+use Math::Prime::Util qw/is_prime next_prime/;
 
 my @perrin_primes = (2,3);
 my ($ppnm3,$ppnm2,$ppnm1, $ppn) = (3,0,2,3);
@@ -27,7 +23,7 @@ while (scalar @perrin_primes < 13) {
 say join ", ", @perrin_primes;
 
 # time: 
-# real	0m0.078s
-# user	0m0.056s
-# sys	0m0.008s
+# real	0m0.025s
+# user	0m0.017s
+# sys	0m0.009s
 
diff --git a/challenge-168/cheok-yin-fung/perl/ch-2.pl b/challenge-168/cheok-yin-fung/perl/ch-2.pl
index 6986c4809a..00406d25ef 100644
--- a/challenge-168/cheok-yin-fung/perl/ch-2.pl
+++ b/challenge-168/cheok-yin-fung/perl/ch-2.pl
@@ -43,6 +43,7 @@ sub my_hp {
             $p = next_prime($p);
         }
         if ($p > sqrt $num) {
+            say "useful";
             push @factors, $num;
             last;
         }
-- 
cgit 


From e66b82a635ca6306adf4b7d46e8b675159e47c8e Mon Sep 17 00:00:00 2001
From: CY Fung <fungcheokyin@gmail.com>
Date: Sun, 12 Jun 2022 11:34:11 +0800
Subject: Task 1 final

---
 challenge-168/cheok-yin-fung/perl/ch-1.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'challenge-168')

diff --git a/challenge-168/cheok-yin-fung/perl/ch-1.pl b/challenge-168/cheok-yin-fung/perl/ch-1.pl
index 3f51cb4766..faf90a9bb3 100644
--- a/challenge-168/cheok-yin-fung/perl/ch-1.pl
+++ b/challenge-168/cheok-yin-fung/perl/ch-1.pl
@@ -4,7 +4,7 @@
 use v5.24.0;
 use warnings;
 use List::Util qw/none/;
-use Math::Prime::Util qw/is_prime next_prime/;
+use Math::Prime::Util qw/is_prime/;
 
 my @perrin_primes = (2,3);
 my ($ppnm3,$ppnm2,$ppnm1, $ppn) = (3,0,2,3);
-- 
cgit 


From 2eb42e251cedc5dfc84e8537f5c5a34a7f3f76bf Mon Sep 17 00:00:00 2001
From: Matthew Neleigh <matthew.neleigh@gmail.com>
Date: Sun, 12 Jun 2022 03:28:29 -0400
Subject: 	new file:   challenge-168/mattneleigh/perl/ch-1.pl 	new
 file:   challenge-168/mattneleigh/perl/ch-2.pl

---
 challenge-168/mattneleigh/perl/ch-1.pl |  99 +++++++++++++++++++++++
 challenge-168/mattneleigh/perl/ch-2.pl | 141 +++++++++++++++++++++++++++++++++
 2 files changed, 240 insertions(+)
 create mode 100755 challenge-168/mattneleigh/perl/ch-1.pl
 create mode 100755 challenge-168/mattneleigh/perl/ch-2.pl

(limited to 'challenge-168')

diff --git a/challenge-168/mattneleigh/perl/ch-1.pl b/challenge-168/mattneleigh/perl/ch-1.pl
new file mode 100755
index 0000000000..3def181d44
--- /dev/null
+++ b/challenge-168/mattneleigh/perl/ch-1.pl
@@ -0,0 +1,99 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use English;
+
+################################################################################
+# Begin main execution
+################################################################################
+
+my @perrin = (3, 0, 2);
+my %perrin_primes = (
+    3 => 1,
+    2 => 1
+);
+my $num = 13;
+
+while(scalar(keys(%perrin_primes)) < $num){
+    next_perrin(\@perrin, 1);
+    $perrin_primes{$perrin[$#perrin]} = 1
+        if(is_prime($perrin[$#perrin]));
+}
+
+print("\n");
+printf(
+    "f(%d) = [%s]\n",
+    $num,
+    join(", ", sort({ $a <=> $b } keys(%perrin_primes)))
+);
+print("\n");
+
+exit(0);
+################################################################################
+# End main execution; subroutines follow
+################################################################################
+
+
+
+################################################################################
+# Calculae the next number in the Perrin sequence, adding it to an existing
+# list of Perrin numbers; see https://en.wikipedia.org/wiki/Perrin_number for
+# details about this type of number
+# Takes one or two arguments:
+# * A ref to a list of Perrin numbers; upon first call to this function, this
+#   list must be [ 3, 0, 2 ]
+# * An agument that, if defined, will cause the first member of the list to be
+#   removed after the new one is added, preventing the list from growing
+# Returns no meaningful value
+################################################################################
+sub next_perrin{
+    my $perrin = shift();
+
+    # Add the next number in the sequence
+    push(
+        @{$perrin},
+        $perrin->[$#$perrin - 2] + $perrin->[$#$perrin - 1]
+    );
+
+    # If specified, toss out the oldest number
+    shift(@{$perrin})
+        if(defined(shift()));
+
+}
+
+
+
+################################################################################
+# Determine whether a given integer N is prime
+# Takes one argument:
+# * The integer N
+# Returns on success:
+# * 1 if N is prime
+# * 0 if N is not prime
+# NOTE: If N is less than zero, it will always be considered nonprime
+################################################################################
+sub is_prime{
+    my $n = int(shift());
+
+    my $i;
+
+    # Take care of a few easy cases
+    return(1)
+        if(($n == 2) || ($n == 3));
+    return(0)
+        if(($n <= 1) || !($n % 2) || !($n % 3));
+
+    # See if certain factors divide evenly
+    for($i = 5; $i * $i <= $n; $i += 6){
+        if(!($n % $i) || !($n % ($i + 2))){
+            return(0);
+        }
+    }
+
+    return(1);
+
+}
+
+
+
diff --git a/challenge-168/mattneleigh/perl/ch-2.pl b/challenge-168/mattneleigh/perl/ch-2.pl
new file mode 100755
index 0000000000..73a5a0962f
--- /dev/null
+++ b/challenge-168/mattneleigh/perl/ch-2.pl
@@ -0,0 +1,141 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use English;
+
+################################################################################
+# Begin main execution
+################################################################################
+
+my $n = 10;
+
+# If you have some time on your hands...
+# $n = 8;
+
+print("\n");
+printf("HP(%d) = %d\n", $n, calculate_home_prime($n));
+print("\n");
+
+exit(0);
+################################################################################
+# End main execution; subroutines follow
+################################################################################
+
+
+
+################################################################################
+# Calculate the home prime of a given integer; see
+# https://en.wikipedia.org/wiki/Home_prime for details about this type of
+# number
+# Takes one argument:
+# * An integer N, which must be at least two (2)
+# Returns on success:
+# * The home prime of N
+# Returns on error:
+# * undef if N is less than two (2)
+# NOTE: For certain values of N, this calculation can take wholly unreasonable
+# amounts of time
+################################################################################
+sub calculate_home_prime{
+    my $n = int(shift());
+
+    return(undef)
+        if($n < 2);
+
+    # Loop until $n is prime
+    until(is_prime($n)){
+        my @factors;
+
+        # Get the prime factors of $n, and concatenate
+        # them into a new $n
+        prime_factorize_number($n, \@factors);
+        $n = join("", @factors);
+    }
+
+    return($n);
+
+}
+
+
+
+################################################################################
+# Find the prime factorization of a given integer
+# Takes two arguments:
+# * The integer N to examine and factor
+# * A ref to a list that will be populated with prime factors in ascending
+#   order; any previous contents will be deleted
+# Returns no meaningful value
+################################################################################
+sub prime_factorize_number{
+    use POSIX;
+
+    my $n = int(shift());
+    my $factors = shift();
+
+    # Clobber existing list contents if any
+    splice(@{$factors}, 0)
+        if(scalar(@{$factors}));
+
+    # Loop until $n is prime
+    until(is_prime($n)){
+        # $n is not prime; set an upper bound on
+        # our factor search
+        my $i;
+        my $max = ceil(sqrt($n));
+
+        # Loop until we find prime $i that
+        # divides evenly into $n
+        for($i=2; $i<=$max; $i++){
+            next unless(is_prime($i));
+            last unless($n % $i);
+        }
+
+        # Store the new prime factor $i and
+        # divide $n by it
+        push(@{$factors}, $i);
+        $n /= $i;
+
+    }
+
+    # Store $n, which by now is the last prime
+    # factor of the originally-supplied argument
+    push(@{$factors}, $n);
+
+}
+
+
+
+################################################################################
+# Determine whether a given integer N is prime
+# Takes one argument:
+# * The integer N
+# Returns on success:
+# * 1 if N is prime
+# * 0 if N is not prime
+# NOTE: If N is less than zero, it will always be considered nonprime
+################################################################################
+sub is_prime{
+    my $n = int(shift());
+
+    my $i;
+
+    # Take care of a few easy cases
+    return(1)
+        if(($n == 2) || ($n == 3));
+    return(0)
+        if(($n <= 1) || !($n % 2) || !($n % 3));
+
+    # See if certain factors divide evenly
+    for($i = 5; $i * $i <= $n; $i += 6){
+        if(!($n % $i) || !($n % ($i + 2))){
+            return(0);
+        }
+    }
+
+    return(1);
+
+}
+
+
+
-- 
cgit 


From d6423b19ceac1cd20b9fd057ce3a82ca16111740 Mon Sep 17 00:00:00 2001
From: Matthew Neleigh <matthew.neleigh@gmail.com>
Date: Sun, 12 Jun 2022 03:33:21 -0400
Subject: 	modified:   challenge-168/mattneleigh/perl/ch-1.pl

---
 challenge-168/mattneleigh/perl/ch-1.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'challenge-168')

diff --git a/challenge-168/mattneleigh/perl/ch-1.pl b/challenge-168/mattneleigh/perl/ch-1.pl
index 3def181d44..9ea3014572 100755
--- a/challenge-168/mattneleigh/perl/ch-1.pl
+++ b/challenge-168/mattneleigh/perl/ch-1.pl
@@ -37,7 +37,7 @@ exit(0);
 
 
 ################################################################################
-# Calculae the next number in the Perrin sequence, adding it to an existing
+# Calculate the next number in the Perrin sequence, adding it to an existing
 # list of Perrin numbers; see https://en.wikipedia.org/wiki/Perrin_number for
 # details about this type of number
 # Takes one or two arguments:
-- 
cgit 


From 8b3d4098625fe8fc4c962796812993aedf893441 Mon Sep 17 00:00:00 2001
From: Stephen Lynn <bizlsg@localhost.localdomain>
Date: Sun, 12 Jun 2022 16:17:37 +0800
Subject:  modified ch-2.jl; tried homeprime(48,65,96)

---
 challenge-168/steve-g-lynn/julia/ch-2.jl | 43 +++++++++++++++++++++++++++++++-
 challenge-168/steve-g-lynn/perl/ch-2.pl  |  8 ++++++
 challenge-168/steve-g-lynn/raku/ch-2.p6  |  7 ++++++
 3 files changed, 57 insertions(+), 1 deletion(-)

(limited to 'challenge-168')

diff --git a/challenge-168/steve-g-lynn/julia/ch-2.jl b/challenge-168/steve-g-lynn/julia/ch-2.jl
index 19d4c7d498..0828857250 100755
--- a/challenge-168/steve-g-lynn/julia/ch-2.jl
+++ b/challenge-168/steve-g-lynn/julia/ch-2.jl
@@ -1,15 +1,56 @@
 #! /usr/bin/julia
 
+#time (bash) output: with homeprime.([10,16,20,48,65,96])
+#real	0m41.340s
+#user	0m41.149s
+#sys	0m0.493s
+
+#-- without homeprime(96):
+#real	0m4.744s
+#user	0m4.745s
+#sys	0m0.467s
+
+#-- without .homeprime.([96,65])
+#real	0m1.072s
+#user	0m1.138s
+#sys	0m0.419s
+
+#-- without .homeprime.([96,65,48])
+#real	0m1.002s
+#user	0m1.095s
+#sys	0m0.384s
+
+
+
 using Primes
 
 function homeprime(n::Int64)
+	return homeprime(BigInt(n))
+end
+
+function homeprime(n::BigInt)
 	ncopy=n
 	while (!isprime(ncopy))
-		ncopy=parse(Int64,join(factor(Vector,ncopy)))
+		ncopy=parse(BigInt,join(factor(Vector,ncopy)))
 	end
 	return ncopy
 end
 
+println(homeprime(10))
+#773
+
 println(homeprime(16))
 #31636373
 
+println(homeprime(20))
+#3318308475676071413
+
+println(homeprime(48))
+#6161791591356884791277
+
+println(homeprime(65))
+#1381321118321175157763339900357651
+
+println(homeprime(96))
+#172929671097972226356946608292031596899264419
+
diff --git a/challenge-168/steve-g-lynn/perl/ch-2.pl b/challenge-168/steve-g-lynn/perl/ch-2.pl
index 379ffd9078..0548ac1ebc 100755
--- a/challenge-168/steve-g-lynn/perl/ch-2.pl
+++ b/challenge-168/steve-g-lynn/perl/ch-2.pl
@@ -5,6 +5,14 @@
 #user	0m0.019s
 #sys	0m0.007s
 
+# but this fast time degrades sharply with larger problems
+#
+# real is 0m45.199s if home_prime(48) also printed
+# real is 5m5.662s if home_prime of 48 and 65 also printed
+# real is 8m50.059s if home_prime of 48, 65 and 96 also printed
+#
+# probably some slowdown in factor(.) for factors of very large primes 
+
 use Math::Prime::Util qw(is_prime factor);
 
 print &home_prime(10),"\n";
diff --git a/challenge-168/steve-g-lynn/raku/ch-2.p6 b/challenge-168/steve-g-lynn/raku/ch-2.p6
index 869bc8b3b5..09cbc4412b 100755
--- a/challenge-168/steve-g-lynn/raku/ch-2.p6
+++ b/challenge-168/steve-g-lynn/raku/ch-2.p6
@@ -5,6 +5,13 @@
 #user	0m0.382s
 #sys	0m0.054s
 
+#time if homeprime(48), homeprime(65) and homeprime(96) are also printed:
+#real	2m23.931s
+#user	2m23.527s
+#sys	0m0.071s
+#
+#  ( real 11.512s with homeprime (10,16,20,48,65)
+#    real 0.922s with homeprime (10,16,20,48) )
 
 use Prime::Factor;
 
-- 
cgit 


From f1dcdae45ca76173c53de4f4f284bfae3a2d9aa3 Mon Sep 17 00:00:00 2001
From: Flavio Poletti <flavio@polettix.it>
Date: Sun, 12 Jun 2022 10:18:43 +0200
Subject: Add polettix's solution to challenge-168

---
 challenge-168/polettix/blog.txt               |  1 +
 challenge-168/polettix/blog1.txt              |  1 +
 challenge-168/polettix/perl/ch-1.pl           | 21 +++++++++++++++
 challenge-168/polettix/perl/ch-2.pl           | 17 ++++++++++++
 challenge-168/polettix/perl/cpanfile          |  1 +
 challenge-168/polettix/perl/cpanfile.snapshot | 38 +++++++++++++++++++++++++++
 challenge-168/polettix/raku/ch-1.raku         | 28 ++++++++++++++++++++
 challenge-168/polettix/raku/ch-2.raku         | 31 ++++++++++++++++++++++
 8 files changed, 138 insertions(+)
 create mode 100644 challenge-168/polettix/blog.txt
 create mode 100644 challenge-168/polettix/blog1.txt
 create mode 100644 challenge-168/polettix/perl/ch-1.pl
 create mode 100644 challenge-168/polettix/perl/ch-2.pl
 create mode 100644 challenge-168/polettix/perl/cpanfile
 create mode 100644 challenge-168/polettix/perl/cpanfile.snapshot
 create mode 100644 challenge-168/polettix/raku/ch-1.raku
 create mode 100644 challenge-168/polettix/raku/ch-2.raku

(limited to 'challenge-168')

diff --git a/challenge-168/polettix/blog.txt b/challenge-168/polettix/blog.txt
new file mode 100644
index 0000000000..f6337130ae
--- /dev/null
+++ b/challenge-168/polettix/blog.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2022/06/08/pwc168-perrin-prime/
diff --git a/challenge-168/polettix/blog1.txt b/challenge-168/polettix/blog1.txt
new file mode 100644
index 0000000000..ad226cc866
--- /dev/null
+++ b/challenge-168/polettix/blog1.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2022/06/09/pwc168-home-prime/
diff --git a/challenge-168/polettix/perl/ch-1.pl b/challenge-168/polettix/perl/ch-1.pl
new file mode 100644
index 0000000000..e4952fb0ed
--- /dev/null
+++ b/challenge-168/polettix/perl/ch-1.pl
@@ -0,0 +1,21 @@
+#!/usr/bin/env perl
+use v5.24;
+use warnings;
+use experimental 'signatures';
+no warnings 'experimental::signatures';
+
+use ntheory 'is_prime';
+
+my $n = shift // 13;
+say join ', ', perrin_primes($n);
+
+sub perrin_primes ($n) {
+   my @pps = (2, 3, 5);
+   my @state = (2, 5, 5);
+   while (@pps < $n) {
+      push @state, my $candidate = $state[0] + $state[1];
+      shift @state;
+      push @pps, $candidate if is_prime($candidate);
+   }
+   return @pps;
+}
diff --git a/challenge-168/polettix/perl/ch-2.pl b/challenge-168/polettix/perl/ch-2.pl
new file mode 100644
index 0000000000..24a1dd1255
--- /dev/null
+++ b/challenge-168/polettix/perl/ch-2.pl
@@ -0,0 +1,17 @@
+#!/usr/bin/env perl
+use v5.24;
+use warnings;
+use experimental 'signatures';
+no warnings 'experimental::signatures';
+
+use ntheory qw< factor >;
+
+my $n = shift // 10;
+say home_prime($n);
+
+sub home_prime {
+   my $next = join '', factor($_[0]);
+   return $next if $next eq $_[0];
+   $_[0] = $next;
+   goto &home_prime;
+}
diff --git a/challenge-168/polettix/perl/cpanfile b/challenge-168/polettix/perl/cpanfile
new file mode 100644
index 0000000000..94ac365d6f
--- /dev/null
+++ b/challenge-168/polettix/perl/cpanfile
@@ -0,0 +1 @@
+requires 'ntheory';
diff --git a/challenge-168/polettix/perl/cpanfile.snapshot b/challenge-168/polettix/perl/cpanfile.snapshot
new file mode 100644
index 0000000000..2fd600a3af
--- /dev/null
+++ b/challenge-168/polettix/perl/cpanfile.snapshot
@@ -0,0 +1,38 @@
+# carton snapshot format: version 1.0
+DISTRIBUTIONS
+  Math-Prime-Util-0.73
+    pathname: D/DA/DANAJ/Math-Prime-Util-0.73.tar.gz
+    provides:
+      Math::Prime::Util 0.73
+      Math::Prime::Util::ChaCha 0.73
+      Math::Prime::Util::Entropy 0.73
+      Math::Prime::Util::MemFree 0.73
+      Math::Prime::Util::PP 0.73
+      Math::Prime::Util::PrimeArray 0.73
+      Math::Prime::Util::PrimeIterator 0.73
+      ntheory 0.73
+    requirements:
+      Carp 0
+      Config 0
+      Exporter 5.57
+      ExtUtils::MakeMaker 0
+      Math::BigFloat 1.59
+      Math::BigInt 1.88
+      Math::Prime::Util::GMP 0.50
+      Tie::Array 0
+      XSLoader 0.01
+      base 0
+      constant 0
+      perl 5.006002
+  Math-Prime-Util-GMP-0.52
+    pathname: D/DA/DANAJ/Math-Prime-Util-GMP-0.52.tar.gz
+    provides:
+      Math::Prime::Util::GMP 0.52
+    requirements:
+      Carp 0
+      Exporter 5.57
+      ExtUtils::MakeMaker 0
+      Fcntl 0
+      XSLoader 0.01
+      base 0
+      perl 5.006002
diff --git a/challenge-168/polettix/raku/ch-1.raku b/challenge-168/polettix/raku/ch-1.raku
new file mode 100644
index 0000000000..28f3b1fb86
--- /dev/null
+++ b/challenge-168/polettix/raku/ch-1.raku
@@ -0,0 +1,28 @@
+#!/usr/bin/env raku
+use v6;
+
+class PerrinSequence {
+   has @!state = [3, 0, 2];
+   method get () {
+      @!state.push(@!state[0] + @!state[1]);
+      return @!state.shift;
+   }
+}
+
+multi sub MAIN (1) { put 2 }
+
+multi sub MAIN (2) { put '2, 3' }
+
+multi sub MAIN (3) { put '2, 3, 5' }
+
+multi sub MAIN (Int:D $n is copy where * > 3 = 13) {
+   my $ps = PerrinSequence.new;
+   $ps.get for 1..7;
+   my @n-primes = gather while $n > 3 {
+      my $candidate = $ps.get;
+      next unless $candidate.is-prime;
+      take $candidate;
+      --$n;
+   }
+   [2, 3, 5, |@n-primes].join(', ').put;
+}
diff --git a/challenge-168/polettix/raku/ch-2.raku b/challenge-168/polettix/raku/ch-2.raku
new file mode 100644
index 0000000000..5de2d6efd4
--- /dev/null
+++ b/challenge-168/polettix/raku/ch-2.raku
@@ -0,0 +1,31 @@
+#!/usr/bin/env raku
+use v6;
+sub MAIN (Int:D $n where * > 1 = 10) { put home-prime($n) }
+
+sub home-prime ($n is copy) {
+   loop {
+      my $m = factors($n).join('').Int;
+      return $n if $n == $m;
+      $n = $m;
+   }
+}
+
+sub factors (Int $remainder is copy) {
+   return 1 if $remainder <= 1;
+   state @primes = 2, 3, 5, -> $n is copy {
+      repeat { $n += 2 } until $n %% none @primes ... { $_ * $_ >= $n }
+      $n;
+   } ... *;
+   gather for @primes -> $factor {
+      if $factor * $factor > $remainder {
+         take $remainder if $remainder > 1;
+         last;
+      }
+
+      # How many times can we divide by this prime?
+      while $remainder %% $factor {
+         take $factor;
+         last if ($remainder div= $factor) === 1;
+      }
+   }
+}
-- 
cgit