solutions for challenge 004

3 files changed, 90 insertions, 0 deletions

diff --git a/challenge-004/adam-russell/blog.txt b/challenge-004/adam-russell/blog.txt
new file mode 100644
index 0000000000..4c79e37d17
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+++ b/challenge-004/adam-russell/blog.txt
@@ -0,0 +1 @@
+https://adamcrussell.livejournal.com/1247.html
diff --git a/challenge-004/adam-russell/perl5/ch-1.pl b/challenge-004/adam-russell/perl5/ch-1.pl
new file mode 100644
index 0000000000..9150261c6b
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+++ b/challenge-004/adam-russell/perl5/ch-1.pl
@@ -0,0 +1,34 @@
+use strict;
+use warnings;
+##
+# Write a script to output the same number of PI digits as the size of your script.
+# Say, if your script size is 10, it should print 3.141592653.
+##
+use bignum;  
+
+sub pi{
+    my($max) = @_;  
+    my @digits;  
+    my($k, $a, $b, $a1, $b1) = (2, 4, 1, 12, 4);  
+    while(@digits < $max){
+        my($p, $q) = ($k ** 2, 2 * $k + 1); 
+        $k = $k + 1;  
+        ($a, $b , $a1, $b1) = ($a1, $b1, $p * $a + $q * $a1, $p * $b + $q * $b1);   
+        my($d, $d1) = (int($a/$b), int($a1/$b1));  
+        while($d == $d1){
+            push @digits, $d;   
+            if(@digits >= $max){
+                return \@digits;  
+            }  
+            ($a, $a1) = (10 * ($a % $b), 10 * ($a1 % $b1));  
+            ($d, $d1) = (int($a / $b), int($a1 / $b1));  
+        }     
+    }  
+    return \@digits;  
+}  
+
+##
+# Main 
+##
+my $digits=pi((stat($0))[7]);  
+print $digits->[0] . "." . join("", @{$digits}[1 .. @{$digits} - 1]); 
diff --git a/challenge-004/adam-russell/perl5/ch-2.pl b/challenge-004/adam-russell/perl5/ch-2.pl
new file mode 100644
index 0000000000..75e57258d4
--- /dev/null
+++ b/challenge-004/adam-russell/perl5/ch-2.pl
@@ -0,0 +1,55 @@
+use strict;
+use warnings;
+##
+# You are given a file containing a list of words (case insensitive 1 word per line) 
+# and a list of letters. Print each word from the file than can be made using only 
+# letters from the list. You can use each letter only once (though there can be 
+# duplicates and you can use each of them once), you don’t have to use all the letters. 
+##
+use boolean;
+
+my @words=qw| 
+    cat
+    mouse
+    rabbit
+    horse
+    sheep
+    cow
+    aardvark
+|; 
+
+my @letters = qw|  
+    a b c e h i o p r s t w b e z      
+|;  
+
+sub contains_remove{
+    my($c) = @_;  
+    return sub{
+        my($word) = @_;  
+        $word =~ s/$c//; 
+        return $word;     
+    }  
+} 
+
+my @checks;
+for my $c (@letters){
+    push @checks, contains_remove(lc($c));  
+} 
+
+sub check_word{
+    my($word, $checks) = @_;
+    if($word && !@{$checks}){
+        return false;  
+    } 
+    $word = &{$checks->[0]}($word);
+    if(!$word){
+        return true;  
+    }  
+    check_word($word, [@{$checks}[1 .. @{$checks} - 1]]);
+}  
+
+for my $w (@words){
+    if(check_word(lc($w), \@checks)){
+        print "$w\n";  
+    }   
+}