Merge remote-tracking branch 'upstream/master'

16 files changed, 368 insertions, 116 deletions

diff --git a/challenge-102/cheok-yin-fung/perl/ch-1.pl b/challenge-102/cheok-yin-fung/perl/ch-1.pl
index eab209da06..2a6a02127e 100644
--- a/challenge-102/cheok-yin-fung/perl/ch-1.pl
+++ b/challenge-102/cheok-yin-fung/perl/ch-1.pl
@@ -55,3 +55,17 @@ for my $k ($bN..$eN) {
 # reasonable time for length = 7 ,
 # be patient for length = 8 (one term, which is palindromic)
 # over 2 min and killed for length = 9 ...
+
+=pod
+// add on March 8th
+$ time perl ch-1.pl 9
+200040002
+204060402
+242484242
+281089082
+291080192
+
+real	10m21.188s
+user	10m19.621s
+sys	0m0.084s
+=cut
diff --git a/challenge-102/feng-chang/raku/ch-1.raku b/challenge-102/feng-chang/raku/ch-1.raku
new file mode 100755
index 0000000000..463aa8f413
--- /dev/null
+++ b/challenge-102/feng-chang/raku/ch-1.raku
@@ -0,0 +1,17 @@
+#!/bin/env raku
+
+sub is-square(UInt:D \N --> Bool:D) {
+    my UInt $n = N.sqrt.UInt;
+    N == $n * $n;
+}
+
+sub MAIN(UInt:D \N) {
+    my UInt $min = ('1' ~ '0' x N-1).UInt;
+    my UInt $max = ('9' x N).UInt;
+    for $min..$max -> $m {
+        my UInt $n = $m.flip.UInt;
+        next if $n > $m;
+
+        put $m if is-square($m + $n) and is-square($m - $n);
+    }
+}
diff --git a/challenge-102/feng-chang/raku/ch-2.raku b/challenge-102/feng-chang/raku/ch-2.raku
new file mode 100755
index 0000000000..394fede9ae
--- /dev/null
+++ b/challenge-102/feng-chang/raku/ch-2.raku
@@ -0,0 +1,15 @@
+#!/bin/env raku
+
+sub MAIN(UInt:D \N) {
+    my Str:D  $s   = '#';
+    my UInt:D $pos = N;
+
+    while $s.chars < N {
+        $s   = $pos ~ $s;
+        $pos = N - $s.chars;
+
+        $s = '#' ~ $s if $s.chars < N;
+    }
+
+    put $s;
+}
diff --git a/challenge-102/james-smith/perl/ch-1.pl b/challenge-102/james-smith/perl/ch-1.pl
index 187ed6b95b..dcfb31af4d 100644
--- a/challenge-102/james-smith/perl/ch-1.pl
+++ b/challenge-102/james-smith/perl/ch-1.pl
@@ -41,10 +41,10 @@ sub rare_numbers {
     my $x = shift;
     return () if $F[$x%9]; ## Digit sum is wrong...
     my $y = reverse $x;
-    return () if $x == $y; ## Musn't be the same back and forth
-    return $y if $x<$y && is_sq($x+$y) && is_sq($y-$x);
+    return () if $x == $y || ! is_sq($x+$y); ## Musn't be the same back and forth
+    return $y if $x<$y && is_sq($y-$x);
+    return $x if $y<$x && is_sq($x-$y);
     ## Check both ways round!
-    return $x if $y<$x && is_sq($x+$y) && is_sq($x-$y);
     return ();
   }
 
diff --git a/challenge-102/paulo-custodio/ada/ch_1.adb b/challenge-102/paulo-custodio/ada/ch_1.adb
index b680983748..a785727689 100644
--- a/challenge-102/paulo-custodio/ada/ch_1.adb
+++ b/challenge-102/paulo-custodio/ada/ch_1.adb
@@ -1,23 +1,23 @@
 -- Challenge 102
--- 
+--
 -- TASK #1 › Rare Numbers
 -- Submitted by: Mohammad S Anwar
--- 
+--
 -- You are given a positive integer $N.
--- 
--- Write a script to generate all Rare numbers of size $N if exists. Please 
+--
+-- Write a script to generate all Rare numbers of size $N if exists. Please
 -- checkout the page for more information about it.
 -- Examples
--- 
+--
 -- (a) 2 digits: 65
 -- (b) 6 digits: 621770
 -- (c) 9 digits: 281089082
 
 with Ada.Command_Line;
-with Ada.Strings.Fixed; 
+with Ada.Strings.Fixed;
  use Ada.Strings.Fixed;
-with Ada.Text_IO; 
- use Ada.Text_IO; 
+with Ada.Text_IO;
+ use Ada.Text_IO;
 with Ada.Numerics.Generic_Elementary_Functions;
 
 procedure ch_1 is
@@ -29,8 +29,8 @@ procedure ch_1 is
 
     -- Sqrt
     package Value_Functions is new Ada.Numerics.Generic_Elementary_Functions(Float);
-    use Value_Functions;    
-    
+    use Value_Functions;
+
     -- convert 1234 to 4321
     function invert_number(a0 : Integer) return integer is
         a : Integer := a0;
@@ -54,7 +54,7 @@ procedure ch_1 is
             return False;
         end if;
     end is_perfect_square;
-    
+
     -- print all rare numbers with n digits
     procedure print_rare_numbers(n : Integer) is
         r1 : Integer;
@@ -71,7 +71,7 @@ procedure ch_1 is
             end if;
         end loop;
     end print_rare_numbers;
-                        
+
 begin
     print_rare_numbers(Integer'Value(CL.Argument(1)));
 end ch_1;
diff --git a/challenge-102/paulo-custodio/ada/ch_2.adb b/challenge-102/paulo-custodio/ada/ch_2.adb
index 7eb1656ec9..48fb10aa2d 100644
--- a/challenge-102/paulo-custodio/ada/ch_2.adb
+++ b/challenge-102/paulo-custodio/ada/ch_2.adb
@@ -1,23 +1,23 @@
 -- Challenge 102
--- 
+--
 -- TASK #2 › Hash-counting String
 -- Submitted by: Stuart Little
--- 
+--
 -- You are given a positive integer $N.
--- 
+--
 -- Write a script to produce Hash-counting string of that length.
--- 
+--
 -- The definition of a hash-counting string is as follows:
 -- - the string consists only of digits 0-9 and hashes, ‘#’
 -- - there are no two consecutive hashes: ‘##’ does not appear in your string
 -- - the last character is a hash
--- - the number immediately preceding each hash (if it exists) is the position 
+-- - the number immediately preceding each hash (if it exists) is the position
 -- of that hash in the string, with the position being counted up from 1
--- 
--- It can be shown that for every positive integer N there is exactly one such 
+--
+-- It can be shown that for every positive integer N there is exactly one such
 -- length-N string.
 -- Examples:
--- 
+--
 -- (a) "#" is the counting string of length 1
 -- (b) "2#" is the counting string of length 2
 -- (c) "#3#" is the string of length 3
@@ -26,7 +26,7 @@
 
 with Ada.Command_Line;
 with Ada.Strings.Fixed; use Ada.Strings.Fixed;
-with Ada.Text_IO; use Ada.Text_IO; 
+with Ada.Text_IO; use Ada.Text_IO;
 
 procedure ch_2 is
     -- command line arguments
@@ -49,7 +49,7 @@ procedure ch_2 is
         end loop;
         return res;
     end hash_count;
-    
-begin 
+
+begin
     Put_Line(hash_count(Integer'Value(CL.Argument(1))));
 end ch_2;
diff --git a/challenge-102/paulo-custodio/basic/ch-1.bas b/challenge-102/paulo-custodio/basic/ch-1.bas
index b33e778d9a..161682f7a8 100644
--- a/challenge-102/paulo-custodio/basic/ch-1.bas
+++ b/challenge-102/paulo-custodio/basic/ch-1.bas
@@ -1,52 +1,52 @@
 ' Challenge 102
-' 
+'
 ' TASK #1 > Rare Numbers
 ' Submitted by: Mohammad S Anwar
-' 
+'
 ' You are given a positive integer $N.
-' 
-' Write a script to generate all Rare numbers of size $N if exists. Please 
+'
+' Write a script to generate all Rare numbers of size $N if exists. Please
 ' checkout the page for more information about it.
 ' Examples
-' 
+'
 ' (a) 2 digits: 65
 ' (b) 6 digits: 621770
 ' (c) 9 digits: 281089082
 
 ' convert 1234 to 4321
 function invert_number(a as Integer) as Integer
-	dim a1 as Integer
-	do while a<>0
-		a1 = a1*10 + (a mod 10)
-		a = int(a / 10)
-	loop
-	invert_number = a1
+    dim a1 as Integer
+    do while a<>0
+        a1 = a1*10 + (a mod 10)
+        a = int(a / 10)
+    loop
+    invert_number = a1
 end function
 
 ' check if number is a perfect square
 function is_perfect_square(n as Integer) as Boolean
-	dim sq as Double
-	sq = sqr(CDbl(n))
-	if int(sq)^2=n then
-		is_perfect_square = True
-	else
-		is_perfect_square = False
-	end if
-end function	
+    dim sq as Double
+    sq = sqr(CDbl(n))
+    if int(sq)^2=n then
+        is_perfect_square = True
+    else
+        is_perfect_square = False
+    end if
+end function
 
 ' print all rare numbers with n digits
 sub print_rare_numbers(n as Integer)
-	dim r as Integer, r1 as Integer
-	for r=10^(n-1) to 10^(n)-1
-		r1 = invert_number(r)
-		if is_perfect_square(r+r1) then
-			if r>=r1 then
-				if is_perfect_square(r-r1) then
-					print trim(str(r))
-				end if
-			end if
-		end if
-	next
+    dim r as Integer, r1 as Integer
+    for r=10^(n-1) to 10^(n)-1
+        r1 = invert_number(r)
+        if is_perfect_square(r+r1) then
+            if r>=r1 then
+                if is_perfect_square(r-r1) then
+                    print trim(str(r))
+                end if
+            end if
+        end if
+    next
 end sub
 
 ' main
diff --git a/challenge-102/paulo-custodio/basic/ch-2.bas b/challenge-102/paulo-custodio/basic/ch-2.bas
index 9987f13b4e..34380d02aa 100644
--- a/challenge-102/paulo-custodio/basic/ch-2.bas
+++ b/challenge-102/paulo-custodio/basic/ch-2.bas
@@ -1,23 +1,23 @@
 ' Challenge 102
-' 
+'
 ' TASK #2 › Hash-counting String
 ' Submitted by: Stuart Little
-' 
+'
 ' You are given a positive integer $N.
-' 
+'
 ' Write a script to produce Hash-counting string of that length.
-' 
+'
 ' The definition of a hash-counting string is as follows:
 ' - the string consists only of digits 0-9 and hashes, ‘#’
 ' - there are no two consecutive hashes: ‘##’ does not appear in your string
 ' - the last character is a hash
-' - the number immediately preceding each hash (if it exists) is the position 
+' - the number immediately preceding each hash (if it exists) is the position
 ' of that hash in the string, with the position being counted up from 1
-' 
-' It can be shown that for every positive integer N there is exactly one such 
+'
+' It can be shown that for every positive integer N there is exactly one such
 ' length-N string.
 ' Examples:
-' 
+'
 ' (a) "#" is the counting string of length 1
 ' (b) "2#" is the counting string of length 2
 ' (c) "#3#" is the string of length 3
@@ -25,19 +25,19 @@
 ' (e) "2#4#6#8#11#14#" is the string of length 14
 
 function hash_count(n as Integer) as String
-	Dim res as String, i as Integer, p as Integer
-	i = n
-	do while i>0
-		p = i
-		res = "#" & res
-		i = i-1
-		do while i>0 and p<>0
-			res = chr(asc("0") + (p mod 10)) & res
-			p = int(p / 10)
-			i = i-1
-		loop
-	loop
-	hash_count = res
+    Dim res as String, i as Integer, p as Integer
+    i = n
+    do while i>0
+        p = i
+        res = "#" & res
+        i = i-1
+        do while i>0 and p<>0
+            res = chr(asc("0") + (p mod 10)) & res
+            p = int(p / 10)
+            i = i-1
+        loop
+    loop
+    hash_count = res
 end function
 
 'main
diff --git a/challenge-102/paulo-custodio/cpp/ch-2.cpp b/challenge-102/paulo-custodio/cpp/ch-2.cpp
index 24fbf2fb06..4832b1d64c 100644
--- a/challenge-102/paulo-custodio/cpp/ch-2.cpp
+++ b/challenge-102/paulo-custodio/cpp/ch-2.cpp
@@ -49,6 +49,6 @@ int main(int argc, char* argv[]) {
         std::cerr << "Usage: ch-1 N" << std::endl;
         return EXIT_FAILURE;
     }
-    else 
+    else
         std::cout << hash_count(atoi(argv[1])) << std::endl;
 }
diff --git a/challenge-102/paulo-custodio/lua/ch-1.lua b/challenge-102/paulo-custodio/lua/ch-1.lua
new file mode 100644
index 0000000000..a24f601c57
--- /dev/null
+++ b/challenge-102/paulo-custodio/lua/ch-1.lua
@@ -0,0 +1,43 @@
+#!/usr/bin/env lua
+
+--[[
+Challenge 102
+
+TASK #1 › Rare Numbers
+Submitted by: Mohammad S Anwar
+
+You are given a positive integer $N.
+
+Write a script to generate all Rare numbers of size $N if exists. Please
+checkout the page for more information about it.
+Examples
+
+(a) 2 digits: 65
+(b) 6 digits: 621770
+(c) 9 digits: 281089082
+--]]
+
+function perfect_square(n)
+    local sq = math.sqrt(n)
+    if math.floor(sq) == sq then
+        return true
+    else
+        return false
+    end
+end
+
+function print_rare(n)
+    for r=10^(n-1),(10^n)-1 do
+        r = math.floor(r)           -- convert to int
+        r1 = tonumber(string.reverse(tostring(r)))
+        if perfect_square(r+r1) then
+            if r >= r1 then
+                if perfect_square(r-r1) then
+                    io.write(r, "\n")
+                end
+            end
+        end
+    end
+end
+
+print_rare(tonumber(arg[1]))
diff --git a/challenge-102/paulo-custodio/lua/ch-2.lua b/challenge-102/paulo-custodio/lua/ch-2.lua
new file mode 100644
index 0000000000..72d378f496
--- /dev/null
+++ b/challenge-102/paulo-custodio/lua/ch-2.lua
@@ -0,0 +1,46 @@
+#!/usr/bin/env lua
+
+--[[
+Challenge 102
+
+TASK #2 > Hash-counting String
+Submitted by: Stuart Little
+
+You are given a positive integer $N.
+
+Write a script to produce Hash-counting string of that length.
+
+The definition of a hash-counting string is as follows:
+- the string consists only of digits 0-9 and hashes, '#'
+- there are no two consecutive hashes: '##' does not appear in your string
+- the last character is a hash
+- the number immediately preceding each hash (if it exists) is the position
+of that hash in the string, with the position being counted up from 1
+
+It can be shown that for every positive integer N there is exactly one such
+length-N string.
+Examples:
+
+(a) "#" is the counting string of length 1
+(b) "2#" is the counting string of length 2
+(c) "#3#" is the string of length 3
+(d) "#3#5#7#10#" is the string of length 10
+(e) "2#4#6#8#11#14#" is the string of length 14
+--]]
+
+function hash_counting(n)
+    local out, i = '', n
+    while i > 0 do
+        p = i
+        out = '#'..out
+        i = i - 1
+        while i > 0 and p ~= 0 do
+            out = tostring(p % 10)..out
+            i = i - 1
+            p = math.floor(p / 10)
+        end
+    end
+    return out
+end
+
+print(hash_counting(tonumber(arg[1])))
diff --git a/challenge-102/paulo-custodio/perl/ch-1.pl b/challenge-102/paulo-custodio/perl/ch-1.pl
index 587ad59d05..644c5cf065 100644
--- a/challenge-102/paulo-custodio/perl/ch-1.pl
+++ b/challenge-102/paulo-custodio/perl/ch-1.pl
@@ -1,16 +1,16 @@
 #!/usr/bin/perl
 
 # Challenge 102
-# 
+#
 # TASK #1 › Rare Numbers
 # Submitted by: Mohammad S Anwar
-# 
+#
 # You are given a positive integer $N.
-# 
-# Write a script to generate all Rare numbers of size $N if exists. Please 
+#
+# Write a script to generate all Rare numbers of size $N if exists. Please
 # checkout the page for more information about it.
 # Examples
-# 
+#
 # (a) 2 digits: 65
 # (b) 6 digits: 621770
 # (c) 9 digits: 281089082
@@ -23,21 +23,21 @@ my($N) = @ARGV or die "Usage: ch-1.pl N\n";
 print_rare($N);
 
 sub print_rare {
-	my($n) = @_;
-	for my $r (10**($n-1) .. 10**($n)-1) {
-		my $r1=0+(join('', reverse split('', $r)));
-		if (perfect_square($r+$r1)) {
-			if ($r>=$r1) {
-				if (perfect_square($r-$r1)) {
-					say $r;
-				}
-			}
-		}
-	}
+    my($n) = @_;
+    for my $r (10**($n-1) .. 10**($n)-1) {
+        my $r1 = reverse $r;
+        if (perfect_square($r+$r1)) {
+            if ($r>=$r1) {
+                if (perfect_square($r-$r1)) {
+                    say $r;
+                }
+            }
+        }
+    }
 }
 
 sub perfect_square {
-	my($n) = @_;
-	my $x = sqrt($n);
-	return ($x == int($x));
+    my($n) = @_;
+    my $x = sqrt($n);
+    return ($x == int($x));
 }
diff --git a/challenge-102/paulo-custodio/perl/ch-2.pl b/challenge-102/paulo-custodio/perl/ch-2.pl
index eac91f4044..64afdc45d6 100644
--- a/challenge-102/paulo-custodio/perl/ch-2.pl
+++ b/challenge-102/paulo-custodio/perl/ch-2.pl
@@ -1,25 +1,25 @@
 #!/usr/bin/perl
 
 # Challenge 102
-# 
+#
 # TASK #2 › Hash-counting String
 # Submitted by: Stuart Little
-# 
+#
 # You are given a positive integer $N.
-# 
+#
 # Write a script to produce Hash-counting string of that length.
-# 
+#
 # The definition of a hash-counting string is as follows:
 # - the string consists only of digits 0-9 and hashes, ‘#’
 # - there are no two consecutive hashes: ‘##’ does not appear in your string
 # - the last character is a hash
-# - the number immediately preceding each hash (if it exists) is the position 
+# - the number immediately preceding each hash (if it exists) is the position
 # of that hash in the string, with the position being counted up from 1
-# 
-# It can be shown that for every positive integer N there is exactly one such 
+#
+# It can be shown that for every positive integer N there is exactly one such
 # length-N string.
 # Examples:
-# 
+#
 # (a) "#" is the counting string of length 1
 # (b) "2#" is the counting string of length 2
 # (c) "#3#" is the string of length 3
@@ -34,15 +34,15 @@ my($N) = @ARGV or die "Usage: ch-1.pl N\n";
 say hash_counting($N);
 
 sub hash_counting {
-	my($n) = @_;
-	my @out;
-	for (my $i = $n; $i>0;) {
-		my $pos = $i;
-		$out[$i--] = '#';
-		while ($i>0 && $pos!=0) {
-			$out[$i--] = $pos%10;
-			$pos = int($pos/10);
-		}
-	}
-	return join('', @out[1..$n]);
+    my($n) = @_;
+    my @out;
+    for (my $i = $n; $i>0;) {
+        my $pos = $i;
+        $out[$i--] = '#';
+        while ($i>0 && $pos!=0) {
+            $out[$i--] = $pos%10;
+            $pos = int($pos/10);
+        }
+    }
+    return join('', @out[1..$n]);
 }
diff --git a/challenge-102/paulo-custodio/python/ch-1.py b/challenge-102/paulo-custodio/python/ch-1.py
new file mode 100644
index 0000000000..d513c19117
--- /dev/null
+++ b/challenge-102/paulo-custodio/python/ch-1.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+
+# Challenge 102
+#
+# TASK #1 > Rare Numbers
+# Submitted by: Mohammad S Anwar
+#
+# You are given a positive integer $N.
+#
+# Write a script to generate all Rare numbers of size $N if exists. Please
+# checkout the page for more information about it.
+# Examples
+#
+# (a) 2 digits: 65
+# (b) 6 digits: 621770
+# (c) 9 digits: 281089082
+
+import sys
+import math
+
+def perfect_square(n):
+    sq = math.sqrt(float(n))
+    if math.floor(sq) == sq:
+        return True
+    else:
+        return False
+
+def print_rare(n):
+    for r in range(10**(n-1), 10**n):
+        r1 = int(str(r)[::-1])
+        if perfect_square(r+r1):
+            if r>=r1:
+                if perfect_square(r-r1):
+                    print(r)
+
+print_rare(int(sys.argv[1]))
diff --git a/challenge-102/paulo-custodio/python/ch-2.py b/challenge-102/paulo-custodio/python/ch-2.py
new file mode 100644
index 0000000000..558367a422
--- /dev/null
+++ b/challenge-102/paulo-custodio/python/ch-2.py
@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+# Challenge 102
+#
+# TASK #2 > Hash-counting String
+# Submitted by: Stuart Little
+#
+# You are given a positive integer $N.
+#
+# Write a script to produce Hash-counting string of that length.
+#
+# The definition of a hash-counting string is as follows:
+# - the string consists only of digits 0-9 and hashes, '#'
+# - there are no two consecutive hashes: '##' does not appear in your string
+# - the last character is a hash
+# - the number immediately preceding each hash (if it exists) is the position
+# of that hash in the string, with the position being counted up from 1
+#
+# It can be shown that for every positive integer N there is exactly one such
+# length-N string.
+# Examples:
+#
+# (a) "#" is the counting string of length 1
+# (b) "2#" is the counting string of length 2
+# (c) "#3#" is the string of length 3
+# (d) "#3#5#7#10#" is the string of length 10
+# (e) "2#4#6#8#11#14#" is the string of length 14
+
+import sys
+
+def hash_counting(n):
+    out = ''
+    i = n
+    while i>0:
+        p = i
+        out = '#'+out
+        i -= 1
+        while i>0 and p!=0:
+            out = str(p % 10)+out
+            i -= 1
+            p = int(p/10)
+    return out
+
+print(hash_counting(int(sys.argv[1])))
diff --git a/challenge-102/yet-ebreo/perl/ch-2.pl b/challenge-102/yet-ebreo/perl/ch-2.pl
new file mode 100644
index 0000000000..4197f1d406
--- /dev/null
+++ b/challenge-102/yet-ebreo/perl/ch-2.pl
@@ -0,0 +1,37 @@
+#! /usr/bin/perl
+
+use strict;
+use warnings;
+use feature qw(say);
+
+
+# You are given a positive integer $N.
+
+# Write a script to produce Hash-counting string of that length.
+
+# The definition of a hash-counting string is as follows:
+
+# - the string consists only of digits 0-9 and hashes, ‘#’
+# - there are no two consecutive hashes: ‘##’ does not appear in your string
+# - the last character is a hash
+# - the number immediately preceding each hash (if it exists) is the position of that hash in the string, with the position being counted up from 1
+# It can be shown that for every positive integer N there is exactly one such length-N string.
+
+# Examples:
+# (a) "#" is the counting string of length 1
+# (b) "2#" is the counting string of length 2
+# (c) "#3#" is the string of length 3
+# (d) "#3#5#7#10#" is the string of length 10
+# (e) "2#4#6#8#11#14#" is the string of length 14
+
+my $N = $ARGV[0] || 2;
+my $out = "";
+
+while ($N) {
+    $out = ($N>1?"$N":"")."#$out";
+    $N   = $ARGV[0] - length $out;
+}
+
+
+say $out;
+