Finished challenge-012 with perl

3 files changed, 78 insertions, 0 deletions

diff --git a/challenge-012/lakpatashi/README b/challenge-012/lakpatashi/README
new file mode 100644
index 0000000000..bc153bd576
--- /dev/null
+++ b/challenge-012/lakpatashi/README
@@ -0,0 +1 @@
+Solution by lakpatashi
diff --git a/challenge-012/lakpatashi/perl/ch-1.pl b/challenge-012/lakpatashi/perl/ch-1.pl
new file mode 100755
index 0000000000..138f208415
--- /dev/null
+++ b/challenge-012/lakpatashi/perl/ch-1.pl
@@ -0,0 +1,48 @@
+#!/usr/bin/perl
+use POSIX;
+use strict;
+use warnings;
+use List::Util qw( min max sum);
+
+
+my $m = 1000000;			# max value for prime list
+my @primes = buildPrimes($m);
+
+my $product = 1 ;
+my $status = 0;
+for my $x (@primes){
+	$product *= $x;
+	#print "iter $x :: $product\n";
+	#print "$product\n";
+	unless(isPrime($product+1)){
+		print "found :: ",$product+1,"\n";
+		$status =1;
+		last;
+	}
+}
+print "Not found" unless($status);
+
+sub buildPrimes{	# building prime list
+	my $m=shift;
+	my @prime = (1)x($m+1);
+	@prime[0,1]=(0)x2;
+	for (my $p=2; $p*$p <= $m; $p++){
+		if($prime[$p]==1){
+			for(my $i= $p*$p; $i<= $m; $i+=$p){
+				$prime[$i]=0;
+			}
+		}
+	}
+	@prime = grep{ $prime[$_] } 2..100;
+	return @prime;
+}
+
+sub isPrime{			# check primality
+	my $n = shift;
+	my $nSq = sqrt $n;
+	for my $i (@primes){
+		last if $i>$nSq;
+		return 0 unless $n % $i;
+	}
+	return 1;
+}
diff --git a/challenge-012/lakpatashi/perl/ch-2.pl b/challenge-012/lakpatashi/perl/ch-2.pl
new file mode 100755
index 0000000000..80334e3e15
--- /dev/null
+++ b/challenge-012/lakpatashi/perl/ch-2.pl
@@ -0,0 +1,29 @@
+#!/usr/bin/perl
+use POSIX;
+use strict;
+use warnings;
+use List::Util qw( min max sum);
+
+my @arr = qw(/a/b/c/d /a/b/cd /a/b/cc /a/b/c/d/e);
+
+my $n = -1;
+my @prevPath;
+for my $x (@arr){
+	my @path = split '/',$x;
+	if ($n == -1){
+		$n = $#path;
+	}else{
+		$n = min($n, $#path);
+		for my $i(reverse 1..$n){
+			if($prevPath[$i] eq $path[$i]){
+				$n = $i;
+				last;
+			}
+			$n = 0 if $i == 1;
+		}
+		print "no common" unless $n;
+	}
+	@prevPath = @path;
+}
+print "base dir:: ",
+join '/', @prevPath[0..$n],"\n" if $n>0;