Merge pull request #7968 from wlmb/challenges

Solve PWC214

3 files changed, 57 insertions, 0 deletions

diff --git a/challenge-214/wlmb/blog.txt b/challenge-214/wlmb/blog.txt
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+++ b/challenge-214/wlmb/blog.txt
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+https://wlmb.github.io/2023/04/24/PWC214/
+
diff --git a/challenge-214/wlmb/perl/ch-1.pl b/challenge-214/wlmb/perl/ch-1.pl
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+++ b/challenge-214/wlmb/perl/ch-1.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 214
+# Task 1:  Rank Score
+#
+# See https://wlmb.github.io/2023/04/24/PWC214/#task-1-rank-score
+use v5.36;
+die <<~"FIN" unless @ARGV;
+    Usage: $0 S1 [S2..]
+    to rank the scores S1 S2...
+    FIN
+my @scores=@ARGV;
+my @ranks=(qw(Gold Silver Bronce), 4..@scores); # G S B 4 5 6...
+my $counter;
+my %score_to_rank;
+map {my $current=$ranks[$counter++]; $score_to_rank{$_}//=$current}
+    sort {$b<=>$a} @scores;
+say join " ", @scores, "->", @score_to_rank{@scores}
diff --git a/challenge-214/wlmb/perl/ch-2.pl b/challenge-214/wlmb/perl/ch-2.pl
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+++ b/challenge-214/wlmb/perl/ch-2.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 214
+# Task 2:  Collect Points
+#
+# See https://wlmb.github.io/2023/04/24/PWC214/#task-2-collect-points
+use v5.36;
+die <<~"FIN" unless @ARGV;
+    Usage: $0 N1 [N2...]
+    to collect all points from the list N1 N2...
+    FIN
+# Build list of nodes, one for each group
+my @list=@ARGV;
+my $first=shift @list;
+my @current=($first, 1);  # nodes are of the form [value, count]
+my @nodes;
+for(@list){
+    push(@nodes, [@current]), @current=($_, 0) unless $current[0] eq $_; # New node if value changes
+    $current[1]++;
+}
+push @nodes, [@current]; # array of pairs [value, count]
+# remove all groups with different starting group and choose largest score
+my @points = sort {$b <=> $a} map {remove($_, \@nodes)} 0..@nodes-1;
+my $points=$points[0]; # largest score
+say "@ARGV -> $points";
+
+# Get max points after removing all $remaining nodes starting from $which
+sub remove($which, $remaining){
+    my @copy=@$remaining;
+    my $points = $copy[$which][1]**2;
+    # join neighbor groups if possible
+    $copy[$which-1]=[$copy[$which-1][0],$copy[$which-1][1]+$copy[$which+1][1]],
+	splice @copy, $which+1,1
+        if 0<$which<@copy-1 && $copy[$which-1][0] eq $copy[$which+1][0];
+    splice @copy, $which, 1;
+    my @points= sort {$b <=> $a} map {remove($_, \@copy)} 0..@copy-1;
+    $points += $points[0] if @points;
+    return $points;
+}