PWC 100 Task 2 Perl LK

1 files changed, 60 insertions, 0 deletions

diff --git a/challenge-100/lubos-kolouch/perl/ch-2.pl b/challenge-100/lubos-kolouch/perl/ch-2.pl
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+++ b/challenge-100/lubos-kolouch/perl/ch-2.pl
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+#!/usr/bin/perl 
+#===============================================================================
+#
+#         FILE: ch_2.pl
+#
+#        USAGE: ./ch_2.pl
+#
+#  DESCRIPTION: Perl Weekly Challenge #100
+#               https://perlweeklychallenge.org/blog/perl-weekly-challenge-100/
+#               Triangle Sum
+#
+#       AUTHOR: Lubos Kolouch
+#      CREATED: 2/20/2021 02:39:16 PM
+#===============================================================================
+
+use strict;
+use warnings;
+
+sub min_sum {
+    my $what = shift;
+
+    #
+    # 1
+    # |\
+    # 2 4
+    # |\|\
+    # 6 4 9
+    # |\|\|\
+    # 5 1 7 2
+
+    my $row_counter = 0;
+    my $min_path;
+    my %sums;
+    for my $row (@$what) {
+        $row_counter++;
+        my $col_counter = 0;
+        for my $item (@$row) {
+            $col_counter++;
+            my $min_sum;
+
+            $min_sum = $sums{$row_counter-1, $col_counter} if exists($sums{$row_counter-1,$col_counter});
+            $min_sum = $sums{$row_counter-1, $col_counter-1} if exists($sums{$row_counter-1,$col_counter-1}) and ( (not $min_sum) or ($sums{$row_counter-1,$col_counter-1} < $min_sum) );
+            $min_sum //= 0;
+
+            $sums{$row_counter,$col_counter} = $item + $min_sum;
+
+            if ($row_counter == scalar @$what) {
+                $min_path = $item + $min_sum if ( (not $min_path) or ($item + $min_sum < $min_path));
+            }
+        }
+    }
+
+    return $min_path;
+}
+use Test::More;
+
+is( min_sum( [ [1], [ 2, 4 ], [ 6, 4, 9 ], [ 5, 1, 7, 2 ] ] ), 8 );
+is( min_sum( [ [3], [3,1], [5,2,3], [4,3,1,3] ] ), 7 );
+
+done_testing;