Week 346

2 files changed, 156 insertions, 0 deletions

diff --git a/challenge-346/zapwai/perl/ch-1.pl b/challenge-346/zapwai/perl/ch-1.pl
new file mode 100644
index 0000000000..7c9bbd6359
--- /dev/null
+++ b/challenge-346/zapwai/perl/ch-1.pl
@@ -0,0 +1,112 @@
+use v5.38;
+sub proc($str) {
+    say "Input: \$str = $str";
+    my (@open, @valid);
+    my @p = split '', $str;
+    for my $i (0 .. $#p) {
+	my $char = $p[$i];
+	next if (@open == 0 && $char eq ')');
+	if (@open == 0) {
+	    push @open, $i;
+	} else {
+	    if ($char eq ')') {
+		push @valid, pop(@open);
+	    } else {
+		push @open, $i;
+	    }
+	}
+    }
+    @valid = sort {$a <=> $b} @valid;
+    my $diff = 0;
+    my $maxdiff = 0;
+    for my $i (0 .. $#valid - 1) {
+	$diff = $valid[$i+1] - $valid[$i];
+	if ($diff > $maxdiff) {
+	    $maxdiff = $diff;
+	}
+    }
+    my $o = "";
+    if ($maxdiff < 3) {
+	$o = 2 * scalar @valid;
+    } else {
+	# Each nest increases valid skip-length by one. (Default is 2)
+	my $skip_len = 2;
+
+	my @val;	 # a multi-array for the non-contiguous case
+	my @curr;	 # the current contiguous block, ref pushed to val
+	for my $i (0 .. $#valid - 1) {
+	    push @curr, $valid[0] if ($i == 0);
+	    $diff = $valid[$i+1] - $valid[$i];
+	    
+	    if ($diff > $skip_len) { # non-contiguous case
+		my @a = @curr;
+		push @val, \@a;
+		@curr = ();
+		$skip_len = 2;
+	    } else {
+		$skip_len -= $diff - 2;
+	    }
+	    push @curr, $valid[$i+1];
+	}
+	push @val, \@curr;
+
+	my $max_len = 0;
+	for my $r (@val) {
+	    my $len = scalar @$r;
+	    $max_len = $len if ($len > $max_len);
+	}
+	
+	$o = 2*$max_len;
+    }
+    say "Output: $o";
+    
+}
+
+my $str = '(()())';
+proc($str);
+$str = ')()())';
+proc($str);
+$str = '((()))()(((()';
+proc($str);
+$str = '))))((()(';
+proc($str);
+$str = '()(()';
+proc($str);
+
+# keep an @open array that holds the index of any opening bracket, the left-hand (
+# when a right-hand ) is encountered, you pop the index off of @open and onto @valid.
+# [right-hand ) are ignored if @open is empty]
+
+# You can then double the length of the largest contiguous block in @valid.
+# (adjacent indices means nested structure, one-space-away means neighboring pairs)
+
+#  first example valid: {0, 1, 3} -> 6
+# second example valid: {1,3} -> 4
+# third valid : {0,1,2,6, 11} -> 8
+# four valid: {6} -> 2
+# five valid: {0,3}  -> 2
+
+
+# # Some Extra Cases
+
+# my $str = '(())()'; # {0, 1, 4} -> 6
+# proc($str);
+# $str = '(())()()'; # {0, 1, 4, 6} -> 8
+# proc($str);
+# $str = '(()(()))()'; # {0, 1, 3, 4, 8} -> 10
+# proc($str);
+# $str = '(()(())())'; # {0, 1, 3, 4, 7} -> 10
+# proc($str);
+
+# # Skip_len decreases when there is an abnormal skip (not a diff of 2, i.e. a closed pair)
+
+# $str = '(()(())()())';
+# proc($str);
+# # {0, 1, 3, 4, 7, 9} -> 12 (skip_len decreases at the 4 to 7 gap.)
+# $str = '(()(())())()';
+# proc($str);
+# # {0, 1, 3, 4, 7, 10} -> 12 (skip_len decreases twice)
+# $str =  '(()(())()))()';
+# proc($str);
+# # {0, 1, 3, 4, 7, 11} -> 10 (gap is larger than skip_len, non-contiguous case)
+
diff --git a/challenge-346/zapwai/perl/ch-2.pl b/challenge-346/zapwai/perl/ch-2.pl
new file mode 100644
index 0000000000..50ff5a55c1
--- /dev/null
+++ b/challenge-346/zapwai/perl/ch-2.pl
@@ -0,0 +1,44 @@
+use v5.38;
+sub proc($str, $target) {
+    say "Input: $str, $target";
+    my @num = split '', $str;
+
+    # This is the single digits case only.
+    # The general version would include (len choose n) cases as n runs from 2 to len - 1
+    # I might upload a more general version later in the week, if I get a chance
+    
+    my @out;
+    my @s = ('+', '-', '*');
+
+    for my $symb (@s) {
+	push @out, $num[0].$symb;
+    }
+
+    for my $i (1 .. $#num - 1) {
+	my @a;
+	for my $symb (@s) {
+	    push @a, $_.$num[$i].$symb for (@out);
+	}
+	@out = @a;
+    }
+
+    my @a;
+    push @a, $_.$num[$#num] for (@out);
+    say "Output: ";
+    for my $a (@a) {
+	my $ans = eval($a);
+	say "\t$a = ".$ans if ($ans == $target);
+    }
+    
+}
+
+my $str = "123"; my $target = 6;
+proc ($str, $target);
+$str = "105"; $target = 5;
+proc ($str, $target);
+$str = "232"; $target = 8;
+proc ($str, $target);
+$str = "1234"; $target = 10;
+proc ($str, $target);
+$str = "1001"; $target = 2;
+proc ($str, $target);