Solutions to challenge-117

2 files changed, 148 insertions, 0 deletions

diff --git a/challenge-117/wanderdoc/perl/ch-1.pl b/challenge-117/wanderdoc/perl/ch-1.pl
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+++ b/challenge-117/wanderdoc/perl/ch-1.pl
@@ -0,0 +1,57 @@
+#!perl
+use strict;
+use warnings FATAL => qw(all);
+
+=prompt
+You are given text file with rows numbered 1-15 in random order but there is a catch one row in missing in the file.
+11, Line Eleven
+1, Line one
+9, Line Nine
+13, Line Thirteen
+2, Line two
+6, Line Six
+8, Line Eight
+10, Line Ten
+7, Line Seven
+4, Line Four
+14, Line Fourteen
+3, Line three
+15, Line Fifteen
+5, Line Five
+Write a script to find the missing row number.
+=cut
+
+
+my %text;
+
+while ( my $line = <DATA> )
+{
+     chomp $line;
+     my ($nr, $row) = split(/\s*,\s*/, $line);
+     $text{$nr} = undef;
+}
+
+my ($min, $max) = (sort {$a <=> $b} keys %text)[0, -1];
+my %check;
+
+$check{$_} = undef for $min .. $max;
+delete @check{ keys %text };
+
+
+print "$_$/" for keys %check; # 12
+
+__END__
+11, Line Eleven
+1, Line one
+9, Line Nine
+13, Line Thirteen
+2, Line two
+6, Line Six
+8, Line Eight
+10, Line Ten
+7, Line Seven
+4, Line Four
+14, Line Fourteen
+3, Line three
+15, Line Fifteen
+5, Line Five
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diff --git a/challenge-117/wanderdoc/perl/ch-2.pl b/challenge-117/wanderdoc/perl/ch-2.pl
new file mode 100644
index 0000000000..63e7ee52ea
--- /dev/null
+++ b/challenge-117/wanderdoc/perl/ch-2.pl
@@ -0,0 +1,91 @@
+#!perl
+use strict;
+use warnings FATAL => qw(all);
+
+
+=prompt
+You are given size of a triangle. Write a script to find all possible paths from top to the bottom right corner.
+In each step, we can either move horizontally to the right (H), or move downwards to the left (L) or right (R).
+
+BONUS: Try if it can handle triangle of size 10 or 20.
+
+Example 1:
+
+Input: $N = 2
+
+           S
+          / \
+         / _ \
+        /\   /\
+       /__\ /__\ E
+
+Output: RR, LHR, LHLH, LLHH, RLH, LRH
+
+
+Example 2:
+
+Input: $N = 1
+
+           S
+          / \
+         / _ \ E
+
+Output: R, LH
+
+=cut
+
+
+my $N = shift or die "Size of triangle? (Warning: Output takes long by size over 10)$/"; # my $N = 10; # 1037718
+my @triangle;
+my $counter = 0;
+for my $i ( 0 .. $N )
+{
+
+     my @row = map $counter++, 0 .. $i;
+
+     push @triangle, [@row];
+}
+
+$counter--; # !
+my %ways = (R => [1, 1], L => [1, 0], H =>[0, 1]);
+
+# my @SOLS; # A way to save output (not recommended by size over 10).
+
+
+sub find_ways
+{
+     my ($triangle, $x, $y, $solution) = @_;
+
+
+     if ($triangle->[$x][$y] == $counter )
+     {
+          my $s = [@$solution];
+
+          print join('-', @$s), $/; # push @SOLS, $s;
+     }
+
+
+
+     for my $w ( keys %ways )
+     {
+          my $next_x = $x + $ways{$w}->[0];
+          my $next_y = $y + $ways{$w}->[1];
+
+          if ( exists $triangle->[$next_x][$next_y] )
+          {
+               push @$solution, $w; 
+
+               if (find_ways($triangle, $next_x, $next_y, $solution))
+               {
+                    return 1;
+               }
+               else
+               {
+                    pop @$solution;
+               }
+
+          }
+     }
+}
+
+find_ways([@triangle], 0, 0, []);
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