Merge pull request #5422 from jaldhar/challenge-143

Challenge 143 by Jaldhar H. Vyas.

5 files changed, 153 insertions, 0 deletions

diff --git a/challenge-143/jaldhar-h-vyas/blog.txt b/challenge-143/jaldhar-h-vyas/blog.txt
new file mode 100644
index 0000000000..3c6f3cadea
--- /dev/null
+++ b/challenge-143/jaldhar-h-vyas/blog.txt
@@ -0,0 +1 @@
+https://www.braincells.com/perl/2021/12/perl_weekly_challenge_week_143.html
diff --git a/challenge-143/jaldhar-h-vyas/perl/ch-1.pl b/challenge-143/jaldhar-h-vyas/perl/ch-1.pl
new file mode 100755
index 0000000000..7d5375d17b
--- /dev/null
+++ b/challenge-143/jaldhar-h-vyas/perl/ch-1.pl
@@ -0,0 +1,39 @@
+#!/usr/bin/perl
+use 5.020;
+use warnings;
+use Parse::RecDescent;
+
+# $RD_HINT = 1;
+
+my $calculator = <<'-EOT-';
+    expression: term(s /([+-])/) {
+        $return = $item[1]->[0];
+
+        for (my $i = 1; $i < scalar @{$item[1]}; $i+=2) {
+            if ($item[1]->[$i] eq q{+}) {
+                $return += $item[1]->[$i + 1];
+            } elsif ($item[1]->[$i] eq q{-}) {
+                $return -= $item[1]->[$i + 1];
+            }
+        }
+    }
+
+    group: '(' expression ')' { $item[2]; }
+
+    term: factor(s /\*/) {
+        $return = 1;
+
+        for my $factor (@{$item[1]}) {
+            $return *= $factor;
+        }
+    }
+
+    factor: number
+        | group
+
+    number: /\-?\d+(\.\d+)?/
+-EOT-
+
+my ($expression) = shift @ARGV // die "Need an expression.\n"; 
+my $parser = new Parse::RecDescent ($calculator);
+say $parser->expression($expression) // die "Parse error.\n";
diff --git a/challenge-143/jaldhar-h-vyas/perl/ch-2.pl b/challenge-143/jaldhar-h-vyas/perl/ch-2.pl
new file mode 100755
index 0000000000..79682f4c99
--- /dev/null
+++ b/challenge-143/jaldhar-h-vyas/perl/ch-2.pl
@@ -0,0 +1,41 @@
+#!/usr/bin/perl
+use 5.020;
+use warnings;
+
+sub combinations {
+    my @list = @{$_[0]};
+    my $length = $_[1];
+
+    if ($length <= 1) {
+        return map [$_], @list;
+    }
+
+    my @combos;
+
+    for (my $i = 0; $i + $length <= scalar @list; $i++) {
+        my $val  = $list[$i];
+        my @rest = @list[$i + 1 .. $#list];
+        for my $c (combinations(\@rest, $length - 1)) {
+            push @combos, [$val, @{$c}] ;
+        }
+    }
+
+    return @combos;
+}
+
+sub isStealthy {
+    my ($n) = @_;
+    my @factorSums = map { $_ + $n / $_; } grep { $n % $_ == 0 } (2 .. $n / 2);
+
+    for my $combo (combinations (\@factorSums, 2)) {
+        if (abs($combo->[0] - $combo->[1]) == 1) {
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+my $n = shift // die "Need an integer.\n";
+
+say isStealthy($n);
\ No newline at end of file
diff --git a/challenge-143/jaldhar-h-vyas/raku/ch-1.raku b/challenge-143/jaldhar-h-vyas/raku/ch-1.raku
new file mode 100755
index 0000000000..cf1a55a1ec
--- /dev/null
+++ b/challenge-143/jaldhar-h-vyas/raku/ch-1.raku
@@ -0,0 +1,62 @@
+#!/usr/bin/raku
+# use Grammar::Tracer;
+
+grammar Calculator {
+    rule TOP { <expression> }
+
+    rule expression {
+        <term>+ % $<op>=(['+'|'-'])
+    }
+
+    rule group { '(' <expression> ')' }
+
+    rule term { <factor>+ % '*' }
+
+    rule factor { <number> | <group> }
+
+    token number { '-'?\d+ ('.' \d+)? }
+}
+
+class CalculatorActions {
+    method TOP($/) {
+        make($<expression>.made);
+    }
+
+    method expression($/) {
+        my $result = $<term>.shift.made;
+
+        if ($<op>) {
+            my @ops = $<op>.map({ $_.Str; });
+            my @values = $<term>.map({ $_.made; });
+ 
+            for @ops -> $op {
+                given $op {
+                    when '+' { $result += @values.shift; }
+                    when '-' { $result -= @values.shift; }
+                }
+            }
+        }
+
+        make($result);
+    }
+
+    method group($/) {
+        make($<expression>.made);
+    }
+
+    method term($/) {
+        make([*] $<factor>.map({ $_.made; }));
+    }
+
+    method number($/) {
+        make $/.Num;
+    }
+
+    method factor($/) {
+        make($<number> ?? $<number>.made !! $<group>.made);
+    }
+}
+
+sub MAIN(Str $expression) {
+    say Calculator.parse($expression, actions => CalculatorActions.new ).made;
+}
\ No newline at end of file
diff --git a/challenge-143/jaldhar-h-vyas/raku/ch-2.raku b/challenge-143/jaldhar-h-vyas/raku/ch-2.raku
new file mode 100755
index 0000000000..c159e1d881
--- /dev/null
+++ b/challenge-143/jaldhar-h-vyas/raku/ch-2.raku
@@ -0,0 +1,10 @@
+#!/usr/bin/raku
+
+sub MAIN(Int $n) {
+    say (2 .. $n div 2)
+        .grep({ $n %% $_ })
+        .map({  [+] ($_, $n div $_) })
+        .combinations(2)
+        .grep({ ([-] $_).abs == 1 })
+        !~~ () ?? 1 !! 0;
+}
\ No newline at end of file