I solved task 2 first and got confused

4 files changed, 189 insertions, 103 deletions

diff --git a/challenge-053/dave-jacoby/node/ch-2.js b/challenge-053/dave-jacoby/node/ch-2.js
new file mode 100644
index 0000000000..b0cd5fa3c6
--- /dev/null
+++ b/challenge-053/dave-jacoby/node/ch-2.js
@@ -0,0 +1,35 @@
+#!/usr/bin/env node
+
+vowel_strings(2);
+
+function vowel_strings(max_len, str = '') {
+  if (str.length === max_len) {
+    console.log(str);
+    return;
+  }
+  var next = [];
+  var last = '';
+
+  if (str.length > 0) {
+    last = str.substring(-1, 1);
+  }
+
+  if (str === '') {
+    next = ['a', 'e', 'i', 'o', 'u'];
+  } else if (last === 'a') {
+    next = ['e', 'i'];
+  } else if (last === 'e') {
+    next = ['i'];
+  } else if (last === 'i') {
+    next = ['a', 'e', 'o', 'u'];
+  } else if (last === 'o') {
+    next = ['a', 'u'];
+  } else if (last === 'u') {
+    next = ['e', 'o'];
+  }
+
+  const iter = next.values();
+  for (const i of iter) {
+    vowel_strings(max_len, str + i);
+  }
+}
diff --git a/challenge-053/dave-jacoby/perl/ch-1.pl b/challenge-053/dave-jacoby/perl/ch-1.pl
index 0e9992e4c2..a81a4ab62d 100644
--- a/challenge-053/dave-jacoby/perl/ch-1.pl
+++ b/challenge-053/dave-jacoby/perl/ch-1.pl
@@ -5,41 +5,82 @@ use warnings;
 use feature qw{ say postderef signatures state };
 no warnings qw{ experimental::postderef experimental::signatures };
 
-my $l = 2;
-if ( scalar @ARGV && int $ARGV[0] > 0 ) { $l = int $ARGV[0] }
+use JSON;
+my $json = JSON->new;
 
-my @strings = vowel_strings($l);
-say join "\n", @strings;
+my $array = [ [ 1 .. 3 ], [ 4 .. 6 ], [ 7 .. 9 ] ];
 
-sub vowel_strings ( $l, $string = '' ) {
-    if ( length $string == $l ) {
-        return $string;
-    }
-    my @next;
-    my $m = length $string == 0 ? '' : substr $string, -1;
-    if ( $string eq '' ) {
-        @next = qw{ a e i o u};
-    }
-    elsif ( $m eq 'a' ) {
-        @next = qw{ e i };
-    }
-    elsif ( $m eq 'e' ) {
-        @next = qw{ i };
-    }
-    elsif ( $m eq 'i' ) {
-        @next = qw{ a o u e };
-    }
-    elsif ( $m eq 'o' ) {
-        @next = qw{ a u };
-    }
-    elsif ( $m eq 'u' ) {
-        @next = qw{ o e };
+my $a90   = rotate_90($array);
+my $a180a = rotate_90($a90);
+my $a270a = rotate_90($a180a);
+my $a360a = rotate_90($a270a);
+
+my $a180b = rotate_180($array);
+my $a270b = rotate_270($array);
+
+say $json->encode($array);
+say '';
+say $json->encode($a90);
+say '';
+say $json->encode($a180a);
+say $json->encode($a180b);
+say '';
+say $json->encode($a270a);
+say $json->encode($a270b);
+say '';
+say $json->encode($a360a);
+
+sub rotate_90( $array ) {
+    my $x      = -1 + scalar $array->@*;
+    my $y      = -1 + scalar $array->[0]->@*;
+    my $output = [];
+    for my $i ( 0 .. $x ) {
+        my $jj = $i;
+        for my $j ( 0 .. $y ) {
+            my $ii = $y - $j;
+            $output->[$i][$j] = int $array->[$ii][$jj];
+        }
     }
+    return $output;
+}
 
-    my @output;
-    for my $n (@next) {
-        push @output, vowel_strings( $l, $string . $n );
+sub rotate_180( $array ) {
+    my $x      = -1 + scalar $array->@*;
+    my $y      = -1 + scalar $array->[0]->@*;
+    my $output = [];
+    for my $i ( 0 .. $x ) {
+        my $jj = $x - $i;
+        for my $j ( 0 .. $y ) {
+            my $ii = $y - $j;
+            $output->[$i][$j] = int $array->[$ii][$jj];
+        }
     }
-    return @output;
+    return $output;
+}
 
+sub rotate_270($array) {
+    my $x      = -1 + scalar $array->@*;
+    my $y      = -1 + scalar $array->[0]->@*;
+    my $output = [];
+    for my $i ( 0 .. $x ) {
+        my $jj = $x - $i;
+        for my $j ( 0 .. $y ) {
+            my $ii = $j;
+            $output->[$i][$j] = int $array->[$ii][$jj];
+        }
+    }
+    return $output;
 }
+
+__DATA__
+
+1 2 3
+4 5 6
+7 8 9
+
+7 4 1
+8 5 2
+9 6 3 
+
+so 0,0 = 2,0
+   0,1 = 3,0
diff --git a/challenge-053/dave-jacoby/perl/ch-2.pl b/challenge-053/dave-jacoby/perl/ch-2.pl
index a81a4ab62d..0e9992e4c2 100644
--- a/challenge-053/dave-jacoby/perl/ch-2.pl
+++ b/challenge-053/dave-jacoby/perl/ch-2.pl
@@ -5,82 +5,41 @@ use warnings;
 use feature qw{ say postderef signatures state };
 no warnings qw{ experimental::postderef experimental::signatures };
 
-use JSON;
-my $json = JSON->new;
+my $l = 2;
+if ( scalar @ARGV && int $ARGV[0] > 0 ) { $l = int $ARGV[0] }
 
-my $array = [ [ 1 .. 3 ], [ 4 .. 6 ], [ 7 .. 9 ] ];
+my @strings = vowel_strings($l);
+say join "\n", @strings;
 
-my $a90   = rotate_90($array);
-my $a180a = rotate_90($a90);
-my $a270a = rotate_90($a180a);
-my $a360a = rotate_90($a270a);
-
-my $a180b = rotate_180($array);
-my $a270b = rotate_270($array);
-
-say $json->encode($array);
-say '';
-say $json->encode($a90);
-say '';
-say $json->encode($a180a);
-say $json->encode($a180b);
-say '';
-say $json->encode($a270a);
-say $json->encode($a270b);
-say '';
-say $json->encode($a360a);
-
-sub rotate_90( $array ) {
-    my $x      = -1 + scalar $array->@*;
-    my $y      = -1 + scalar $array->[0]->@*;
-    my $output = [];
-    for my $i ( 0 .. $x ) {
-        my $jj = $i;
-        for my $j ( 0 .. $y ) {
-            my $ii = $y - $j;
-            $output->[$i][$j] = int $array->[$ii][$jj];
-        }
+sub vowel_strings ( $l, $string = '' ) {
+    if ( length $string == $l ) {
+        return $string;
     }
-    return $output;
-}
-
-sub rotate_180( $array ) {
-    my $x      = -1 + scalar $array->@*;
-    my $y      = -1 + scalar $array->[0]->@*;
-    my $output = [];
-    for my $i ( 0 .. $x ) {
-        my $jj = $x - $i;
-        for my $j ( 0 .. $y ) {
-            my $ii = $y - $j;
-            $output->[$i][$j] = int $array->[$ii][$jj];
-        }
+    my @next;
+    my $m = length $string == 0 ? '' : substr $string, -1;
+    if ( $string eq '' ) {
+        @next = qw{ a e i o u};
     }
-    return $output;
-}
-
-sub rotate_270($array) {
-    my $x      = -1 + scalar $array->@*;
-    my $y      = -1 + scalar $array->[0]->@*;
-    my $output = [];
-    for my $i ( 0 .. $x ) {
-        my $jj = $x - $i;
-        for my $j ( 0 .. $y ) {
-            my $ii = $j;
-            $output->[$i][$j] = int $array->[$ii][$jj];
-        }
+    elsif ( $m eq 'a' ) {
+        @next = qw{ e i };
+    }
+    elsif ( $m eq 'e' ) {
+        @next = qw{ i };
+    }
+    elsif ( $m eq 'i' ) {
+        @next = qw{ a o u e };
+    }
+    elsif ( $m eq 'o' ) {
+        @next = qw{ a u };
+    }
+    elsif ( $m eq 'u' ) {
+        @next = qw{ o e };
     }
-    return $output;
-}
-
-__DATA__
-
-1 2 3
-4 5 6
-7 8 9
 
-7 4 1
-8 5 2
-9 6 3 
+    my @output;
+    for my $n (@next) {
+        push @output, vowel_strings( $l, $string . $n );
+    }
+    return @output;
 
-so 0,0 = 2,0
-   0,1 = 3,0
+}
diff --git a/challenge-053/dave-jacoby/rust/ch-2.rs b/challenge-053/dave-jacoby/rust/ch-2.rs
new file mode 100644
index 0000000000..086987ff5b
--- /dev/null
+++ b/challenge-053/dave-jacoby/rust/ch-2.rs
@@ -0,0 +1,51 @@
+fn main() {
+    let my_str = "".to_string();
+    vowel_strings(2,my_str);
+}
+
+fn vowel_strings ( max_len:i32 , my_str:String) -> bool {
+    let rts_ym : String = my_str.chars().rev().collect();
+    let my_len = my_str.len();
+    let mut last = "";
+    let mut vnext : Vec<String> = Vec::new();
+
+    if  max_len as usize == my_len {
+        println!("{}",my_str);
+        return true
+    }
+
+    if my_len > 0 {
+        last = &rts_ym[0..1];
+    }
+
+    if  last == "a" {
+        vnext.push("e".to_string());
+        vnext.push("i".to_string());
+    } else if last == "e" {
+        vnext.push("i".to_string());
+    } else if last == "i" {
+        vnext.push("a".to_string());
+        vnext.push("e".to_string());
+        vnext.push("o".to_string());
+        vnext.push("u".to_string());
+    } else if last == "o" {
+        vnext.push("a".to_string());
+        vnext.push("o".to_string());
+    } else if last == "u" {
+        vnext.push("e".to_string());
+        vnext.push("o".to_string());
+    } else {
+        vnext.push("a".to_string());
+        vnext.push("e".to_string());
+        vnext.push("i".to_string());
+        vnext.push("o".to_string());
+        vnext.push("u".to_string());
+
+    }
+
+    for next in &vnext {
+        let next_str = format!("{}{}",my_str,next);
+        vowel_strings(max_len,next_str);
+    }
+    true
+}
\ No newline at end of file