Add solution 197 by Thomas Köhler

Signed-off-by: Thomas Köhler <jean-luc@picard.franken.de>

4 files changed, 85 insertions, 0 deletions

diff --git a/challenge-197/jeanluc2020/blog-1.txt b/challenge-197/jeanluc2020/blog-1.txt
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@@ -0,0 +1 @@
+http://gott-gehabt.de/800_wer_wir_sind/thomas/Homepage/Computer/perl/theweeklychallenge-197-1.html
diff --git a/challenge-197/jeanluc2020/blog-2.txt b/challenge-197/jeanluc2020/blog-2.txt
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+++ b/challenge-197/jeanluc2020/blog-2.txt
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+http://gott-gehabt.de/800_wer_wir_sind/thomas/Homepage/Computer/perl/theweeklychallenge-197-2.html
diff --git a/challenge-197/jeanluc2020/perl/ch-1.pl b/challenge-197/jeanluc2020/perl/ch-1.pl
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+#!/usr/bin/perl
+# https://theweeklychallenge.org/blog/perl-weekly-challenge-197/#TASK1
+#
+# You are given a list of integers, @list.
+#
+# Write a script to move all zero, if exists, to the end while maintaining the relative order of non-zero elements.
+
+use strict;
+use warnings;
+
+# sample input values
+my $inputs = [
+    [1, 0, 3, 0, 0, 5],
+    [1, 6, 4],
+    [0, 1, 0, 2, 0]
+];
+
+# handle all input arrays from sample list above
+foreach my $input (@$inputs) {
+   print "(" . join(", ", @$input) . ") returns (" . join(", ", move_zero(@$input)) . ")\n";
+}
+
+# given a list of integers, return the same list with all zeros moved to the end
+sub move_zero {
+   my @values = @_;
+   my @return = ();
+   my @tmp = ();
+   # collect all non-zero values into @return, all zero values into @tmp
+   foreach my $elem (@values) {
+      if($elem == 0) {
+         push @tmp, $elem;
+      } else {
+         push @return, $elem;
+      }
+   }
+   # add all zero values to the end of @return before returning
+   push @return, @tmp;
+   return @return;
+}
diff --git a/challenge-197/jeanluc2020/perl/ch-2.pl b/challenge-197/jeanluc2020/perl/ch-2.pl
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+++ b/challenge-197/jeanluc2020/perl/ch-2.pl
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+#!/usr/bin/perl
+# https://theweeklychallenge.org/blog/perl-weekly-challenge-197/#TASK2
+#
+# You are given a list of integers, @list.
+#
+# Write a script to perform Wiggle Sort on the given list.
+#
+# # Wiggle sort would be such as list[0] < list[1] > list[2] < list[3]...
+
+use strict;
+use warnings;
+
+# sample input values
+my $inputs = [
+   [1,5,1,1,6,4],
+   [1,3,2,2,3,1],
+   [1,2,3,4,5],
+   [1,1,1,2,2,2,3,3,4,4],
+];
+
+# handle all input arrays from sample list above
+foreach my $input (@$inputs) {
+   print "(" . join(", ", @$input) . ") returns (" . join(", ", wiggle_sort(@$input)) . ")\n";
+}
+
+# wiggle sort has to jump up and down every time
+sub wiggle_sort {
+   # let's start by sorting all values
+   my @values = sort {$a <=> $b} @_;
+   my @result = ();
+   # by starting in the middle of the sorted array and walking down while at
+   # the same time starting at the top and wakling down as well, we can always
+   # make sure we have a bigger and a smaller value next to each other
+   my $start = int($#values/2);
+   my ($i, $j) = ($start, $#values);
+   while($i >= 0 && $j > $start) {
+      push @result, $values[$i--], $values[$j--];
+   }
+   # if we have an odd number of values in the original array, we now have
+   # one more value to take care of; in this case $i just reached 0 by means of
+   # the last "$i--" in the loop
+   push @result, $values[$i] if $i == 0;
+   return @result;
+}