Merge pull request #1096 from wanderdoc/master

Solutions from wanderdoc. Happy New Year!

4 files changed, 251 insertions, 0 deletions

diff --git a/challenge-041/wanderdoc/R/ch-01.R b/challenge-041/wanderdoc/R/ch-01.R
new file mode 100644
index 0000000000..36ab135753
--- /dev/null
+++ b/challenge-041/wanderdoc/R/ch-01.R
@@ -0,0 +1,80 @@
+decomp <- function(x)
+{
+  num <- x
+  
+  div_max <-num/2
+  fct<-numeric(0)
+  if(x <=3) {return(fct)} # because of for loop below.
+  
+  for(i in 2:div_max)
+  {
+    while( 0 == x%%i)
+    {
+
+      fct <- c(fct, i) 
+      x = x/i
+    }
+  }
+  fct<-fct[!is.na(fct)]
+}
+
+# https://stackoverflow.com/questions/3789968 , here slightly modified to match 2 too:
+
+isPrime <- function(x)
+{
+  div <- 2:ceiling(sqrt(x))
+
+  !any(x %% div == 0) || 2 == x
+}
+
+print_attractive <- function(x)
+{
+  factors <- decomp(x)
+  size <- length(factors)
+  if(size > 0 && isPrime(size)) 
+     {
+       print(paste(x, paste(factors, collapse=" x "), sep = " = "))
+     }
+}
+
+
+for (i in 1:50)
+{
+  print_attractive(i)
+}
+
+
+
+
+
+# Prints:
+# [1] "4 = 2 x 2"
+# [1] "6 = 2 x 3"
+# [1] "8 = 2 x 2 x 2"
+# [1] "9 = 3 x 3"
+# [1] "10 = 2 x 5"
+# [1] "12 = 2 x 2 x 3"
+# [1] "14 = 2 x 7"
+# [1] "15 = 3 x 5"
+# [1] "18 = 2 x 3 x 3"
+# [1] "20 = 2 x 2 x 5"
+# [1] "21 = 3 x 7"
+# [1] "22 = 2 x 11"
+# [1] "25 = 5 x 5"
+# [1] "26 = 2 x 13"
+# [1] "27 = 3 x 3 x 3"
+# [1] "28 = 2 x 2 x 7"
+# [1] "30 = 2 x 3 x 5"
+# [1] "32 = 2 x 2 x 2 x 2 x 2"
+# [1] "33 = 3 x 11"
+# [1] "34 = 2 x 17"
+# [1] "35 = 5 x 7"
+# [1] "38 = 2 x 19"
+# [1] "39 = 3 x 13"
+# [1] "42 = 2 x 3 x 7"
+# [1] "44 = 2 x 2 x 11"
+# [1] "45 = 3 x 3 x 5"
+# [1] "46 = 2 x 23"
+# [1] "48 = 2 x 2 x 2 x 2 x 3"
+# [1] "49 = 7 x 7"
+# [1] "50 = 2 x 5 x 5"
\ No newline at end of file
diff --git a/challenge-041/wanderdoc/R/ch-02.R b/challenge-041/wanderdoc/R/ch-02.R
new file mode 100644
index 0000000000..397aa8cb93
--- /dev/null
+++ b/challenge-041/wanderdoc/R/ch-02.R
@@ -0,0 +1,29 @@
+fib <- function(n) 
+{
+  x <- 0; y <- 1;
+
+  m <- 0;
+  while (m < n)
+  {
+    temp <-x;
+    x <- y;
+    y <- temp + y;
+    m = m + 1;
+  }
+
+  x
+}
+
+
+leonardo <- function(x)
+{
+  leo_num <- 2 * fib(x + 1) - 1
+  leo_num
+}
+
+
+sapply(1:20, leonardo)
+
+# Prints:
+# [1]     1     3     5     9    15    25    41    67   109   177   287   465   753  1219  1973
+# [16]  3193  5167  8361 13529 21891
diff --git a/challenge-041/wanderdoc/perl5/ch-01.pl b/challenge-041/wanderdoc/perl5/ch-01.pl
new file mode 100644
index 0000000000..c49ee37479
--- /dev/null
+++ b/challenge-041/wanderdoc/perl5/ch-01.pl
@@ -0,0 +1,99 @@
+#!perl
+use strict;
+use warnings FATAL => qw(all);
+
+=prompt
+Write a script to display attractive number between 1 and 50.
+    A number is an attractive number if the number of its prime factors is also prime number.
+=cut
+
+
+
+
+
+
+my $N = shift || 50; # or die "How much is the number?\n";
+
+for ( 1 .. $N ) 
+{ 
+     print_attractive($_); 
+}
+
+=output
+4 = 2 * 2
+6 = 2 * 3
+8 = 2 * 2 * 2
+9 = 3 * 3
+10 = 2 * 5
+12 = 2 * 2 * 3
+14 = 2 * 7
+15 = 3 * 5
+18 = 2 * 3 * 3
+20 = 2 * 2 * 5
+21 = 3 * 7
+22 = 2 * 11
+25 = 5 * 5
+26 = 2 * 13
+27 = 3 * 3 * 3
+28 = 2 * 2 * 7
+30 = 2 * 3 * 5
+32 = 2 * 2 * 2 * 2 * 2
+33 = 3 * 11
+34 = 2 * 17
+35 = 5 * 7
+38 = 2 * 19
+39 = 3 * 13
+42 = 2 * 3 * 7
+44 = 2 * 2 * 11
+45 = 3 * 3 * 5
+46 = 2 * 23
+48 = 2 * 2 * 2 * 2 * 3
+49 = 7 * 7
+50 = 2 * 5 * 5
+=cut
+
+sub print_attractive
+{
+     my $n = $_[0];
+
+     my $n_orig = $n;
+     my $counter = 0;
+
+     my @factors;
+
+     # Old nice one-liner for prime factorization:
+     # perl -le "$x = shift; for $k (2 .. $x/2) {$x%$k or (print $k and $x /= $k and redo) }"
+
+
+     for my $k ( 2 .. $n/2 )
+     {
+          0 == $n % $k and
+               $factors[$counter++] = $k and
+               $n /= $k and redo;
+     }
+     print join(" ", $n_orig, '=', join(' * ',@factors)), $/ if is_prime($counter);
+}
+
+
+# https://en.wikipedia.org/wiki/Primality_test
+
+sub is_prime
+{
+     my $n = $_[0];
+     if ($n <= 3) {return $n > 1 ? 1 : 0;}
+     elsif (0 == $n % 2 or 0 == $n % 3) {return 0;}
+
+     else
+     {
+          my $i = 5;
+          while ( $i * $i <= $n )
+          {
+               if ( 0 == $n % $i or 0 == $n % ($i + 2))
+               {
+                    return 0;
+               }
+               $i += 6; 
+          }
+     }
+    return 1;
+}
\ No newline at end of file
diff --git a/challenge-041/wanderdoc/perl5/ch-02.pl b/challenge-041/wanderdoc/perl5/ch-02.pl
new file mode 100644
index 0000000000..3a9532d5a0
--- /dev/null
+++ b/challenge-041/wanderdoc/perl5/ch-02.pl
@@ -0,0 +1,43 @@
+#!perl
+use strict;
+use warnings FATAL => qw(all);
+
+=prompt
+Write a script to display first 20 Leonardo Numbers.
+
+a(n) = 2 * Fibonacci(n+1) - 1. - Richard L. Ollerton Mar 22 2002.
+https://oeis.org/A001595
+
+First 20 Leonardo numbers (first being No.0):
+1, 1, 3, 5, 9, 15, 25, 41, 67, 109, 177, 287, 465, 753, 1219, 1973, 3193, 5167, 8361, 13529, 21891
+=cut
+
+# use bigint; # If you will 500 numbers or so :-).
+
+my $fn = shift || 20; #  or die "How much numbers?\n";
+print join(" ", map 2 * fib($_ + 1) - 1, 0 .. 20), $/;
+
+=output
+1 1 3 5 9 15 25 41 67 109 177 287 465 753 1219 1973 3193 5167 8361 13529 21891
+=cut
+
+
+# Algorithm found at:
+# https://stackoverflow.com/questions/494594
+
+sub fib
+{
+     my $n = shift;
+     my $x = 0; 
+     my $y = 1;
+
+     my $m = 0; 
+     while ( $m < $n )
+     {
+          ($x, $y) = ($y, $x + $y);
+          $m++;
+
+     }
+
+     return $x;
+}