Merge pull request #6241 from steve-g-lynn/new-branch

faster ch-2.pl & ch-2.p6 using external libs

3 files changed, 71 insertions, 64 deletions

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 5fe95544ad..0548ac1ebc 100755
--- a/challenge-168/steve-g-lynn/perl/ch-2.pl
+++ b/challenge-168/steve-g-lynn/perl/ch-2.pl
@@ -1,6 +1,19 @@
 #!/usr/bin/perl
 
-use Math::Prime::XS qw(is_prime);
+#time (bash) output:
+#real	0m0.026s
+#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";
 #773
@@ -14,37 +27,9 @@ 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..09cbc4412b 100755
--- a/challenge-168/steve-g-lynn/raku/ch-2.p6
+++ b/challenge-168/steve-g-lynn/raku/ch-2.p6
@@ -1,10 +1,19 @@
 #!/usr/bin/raku
 
 #time (bash command): 
-#real	0m0.511s
-#user	0m0.622s
-#sys	0m0.046s
+#real	0m0.312s
+#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;
 
 say homeprime(10);
 #773
@@ -15,37 +24,9 @@ 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);
 }