Add solution 280.

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

4 files changed, 115 insertions, 0 deletions

diff --git a/challenge-280/jeanluc2020/blog-1.txt b/challenge-280/jeanluc2020/blog-1.txt
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+++ b/challenge-280/jeanluc2020/blog-1.txt
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+http://gott-gehabt.de/800_wer_wir_sind/thomas/Homepage/Computer/perl/theweeklychallenge-280-1.html
diff --git a/challenge-280/jeanluc2020/blog-2.txt b/challenge-280/jeanluc2020/blog-2.txt
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index 0000000000..be3d90626a
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+++ b/challenge-280/jeanluc2020/blog-2.txt
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+http://gott-gehabt.de/800_wer_wir_sind/thomas/Homepage/Computer/perl/theweeklychallenge-280-2.html
diff --git a/challenge-280/jeanluc2020/perl/ch-1.pl b/challenge-280/jeanluc2020/perl/ch-1.pl
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+++ b/challenge-280/jeanluc2020/perl/ch-1.pl
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+#!/usr/bin/env perl
+# https://theweeklychallenge.org/blog/perl-weekly-challenge-280/#TASK1
+#
+# Task 1: Twice Appearance
+# ========================
+#
+# You are given a string, $str, containing lowercase English letters only.
+#
+# Write a script to print the first letter that appears twice.
+#
+## Example 1
+##
+## Input: $str = "acbddbca"
+## Output: "d"
+#
+## Example 2
+##
+## Input: $str = "abccd"
+## Output: "c"
+#
+## Example 3
+##
+## Input: $str = "abcdabbb"
+## Output: "a"
+#
+############################################################
+##
+## discussion
+##
+############################################################
+#
+# Read one character at a time, and return it if it was already
+# in the string before.
+
+use strict;
+use warnings;
+
+twice_appearance("acbddbca");
+twice_appearance("abccd");
+twice_appearance("abcdabbb");
+
+sub twice_appearance {
+   my $str = shift;
+   my $seen = {};
+   print "Input: \"$str\"\n";
+   foreach my $char (split //, $str) {
+      return print "Output: $char\n" if $seen->{$char};
+      $seen->{$char} = 1;
+   }
+   print "Output: None\n";
+}
diff --git a/challenge-280/jeanluc2020/perl/ch-2.pl b/challenge-280/jeanluc2020/perl/ch-2.pl
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+++ b/challenge-280/jeanluc2020/perl/ch-2.pl
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+#!/usr/bin/env perl
+# https://theweeklychallenge.org/blog/perl-weekly-challenge-280/#TASK2
+#
+# Task 2: Count Asterisks
+# =======================
+#
+# You are given a string, $str, where every two consecutive vertical bars are
+# grouped into a pair.
+#
+# Write a script to return the number of asterisks, *, excluding any between
+# each pair of vertical bars.
+#
+## Example 1
+##
+## Input: $str = "p|*e*rl|w**e|*ekly|"
+## Ouput: 2
+##
+## The characters we are looking here are "p" and "w**e".
+#
+## Example 2
+##
+## Input: $str = "perl"
+## Ouput: 0
+#
+## Example 3
+##
+## Input: $str = "th|ewe|e**|k|l***ych|alleng|e"
+## Ouput: 5
+##
+## The characters we are looking here are "th", "e**", "l***ych" and "e".
+#
+############################################################
+##
+## discussion
+##
+############################################################
+#
+# Split $str at | characters, and then only look at the odd
+# ones. Split those into single characters and count the stars.
+
+use strict;
+use warnings;
+
+count_asterisks("p|*e*rl|w**e|*ekly|");
+count_asterisks("perl");
+count_asterisks("th|ewe|e**|k|l***ych|alleng|e");
+
+sub count_asterisks {
+   my $str = shift;
+   my @parts = split /\|/, $str;
+   my $index = 0;
+   my $count = 0;
+   print "Input: \"$str\"\n";
+   foreach my $part (@parts) {
+      $index++;
+      next unless $index % 2;
+      foreach my $char (split //, $part) {
+         $count++ if $char eq '*';
+      }
+   }
+   print "Output: $count\n";
+}