Merge pull request #3122 from akarelas/challenge-093

solutions to #093

2 files changed, 107 insertions, 0 deletions

diff --git a/challenge-093/alexander-karelas/perl/ch-1.pl b/challenge-093/alexander-karelas/perl/ch-1.pl
new file mode 100755
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+++ b/challenge-093/alexander-karelas/perl/ch-1.pl
@@ -0,0 +1,41 @@
+#!/usr/bin/env perl
+#
+# You are given set of co-ordinates @N. Write a script to count maximum points on a straight line when given
+# co-ordinates plotted on 2-d plane.
+
+use v5.30;
+use warnings;
+
+use Test::More;
+use List::Util 'max';
+
+sub maximum_points {
+    my @points = @_;
+
+    my %lines = (
+        x  => {},
+        y  => {},
+        d1 => {},
+        d2 => {},
+    );
+
+    foreach my $point (@points) {
+        $lines{x}{$point->[0]}++;
+        $lines{y}{$point->[1]}++;
+        $lines{d1}{$point->[0] - $point->[1]}++;
+        $lines{d2}{$point->[0] + $point->[1]}++;
+    }
+
+    my @lines;
+    foreach my $hashset (values %lines) {
+        push @lines, values %$hashset;
+    }
+
+    return max(@lines);
+}
+
+is maximum_points([1,1], [2,2], [3,3]), 3, '1st example';
+is maximum_points([1,1], [2,2], [3,1], [1,3], [5,3]), 3, '2nd example';
+is maximum_points([1,1], [2,1], [3,1], [4,1], [2,2]), 4, 'extra example';
+
+done_testing;
\ No newline at end of file
diff --git a/challenge-093/alexander-karelas/perl/ch-2.pl b/challenge-093/alexander-karelas/perl/ch-2.pl
new file mode 100755
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+++ b/challenge-093/alexander-karelas/perl/ch-2.pl
@@ -0,0 +1,66 @@
+#!/usr/bin/env perl
+#
+# You are given binary tree containing numbers 0-9 only.
+# Write a script to sum all possible paths from root to leaf.
+
+use v5.30;
+use warnings;
+
+use Test::More;
+
+use List::Util 'sum';
+
+sub find_path_sums {
+    my ($tree, $node_key, $path_sum) = @_;
+
+    $path_sum += $node_key;
+    my $node = $tree->{$node_key};
+    my @path_sums;
+    if (!defined $node->{left} and !defined $node->{right}) {
+        @path_sums = ($path_sum);
+        return \@path_sums;
+    }
+    push @path_sums, find_path_sums($tree, $node->{left}, $path_sum)->@* if $node->{left};
+    push @path_sums, find_path_sums($tree, $node->{right}, $path_sum)->@* if $node->{right};
+
+    return \@path_sums;
+}
+
+sub sum_path {
+    my ($tree) = @_;
+
+    my $root_node = do {
+        my %values = %$tree;
+        delete @values{($_->{left} // (), $_->{right} // ())} foreach values %$tree;
+        (keys %values)[0];
+    };
+
+    my @paths_sums = find_path_sums($tree, $root_node, 0)->@*;
+    return sum(@paths_sums);
+}
+
+
+# example 1
+my %tree = (
+    1 => { left => 2 },
+    2 => { left => 3, right => 4 },
+    3 => {},
+    4 => {},
+);
+
+is sum_path(\%tree), 13, '1st example';
+
+
+# example 2
+%tree = (
+    1 => { left => 2, right => 3 },
+    2 => { left => 4 },
+    3 => { left => 5, right => 6 },
+    4 => {},
+    5 => {},
+    6 => {},
+);
+
+is sum_path(\%tree), 26, '2nd example';
+
+done_testing();