March 2014 update

Task/Best-shuffle/D/best-shuffle-1.d

@@ -1,40 +1,41 @@
 import std.stdio, std.random, std.algorithm, std.conv, std.range,
-std.traits, std.typecons;
+       std.traits, std.typecons;
 
 auto bestShuffle(S)(in S orig) if (isSomeString!S) {
     static if (isNarrowString!S)
-        auto o = to!dstring(orig);
-    else alias orig o;
+        immutable o = orig.dtext;
+    else
+        alias o = orig;
 
     auto s = o.dup;
-    randomShuffle(s);
-    foreach (i, ref ci; s) {
+    s.randomShuffle;
+
+    foreach (immutable i, ref ci; s) {
         if (ci != o[i])
             continue;
-        foreach (j, ref cj; s)
+        foreach (immutable j, ref cj; s)
             if (ci != cj && ci != o[j] && cj != o[i]) {
                 swap(ci, cj);
                 break;
             }
     }
-    return tuple(s, count!"a[0] == a[1]"(zip(s, o)));
+
+    return tuple(s, s.zip(o).count!q{ a[0] == a[1] });
+} unittest {
+    assert("abracadabra".bestShuffle[1] == 0);
+    assert("immediately".bestShuffle[1] == 0);
+    assert("grrrrrr".bestShuffle[1] == 5);
+    assert("seesaw".bestShuffle[1] == 0);
+    assert("pop".bestShuffle[1] == 1);
+    assert("up".bestShuffle[1] == 0);
+    assert("a".bestShuffle[1] == 1);
+    assert("".bestShuffle[1] == 0);
 }
 
-unittest {
-    assert(bestShuffle("abracadabra"d)[1] == 0);
-    assert(bestShuffle("immediately"d)[1] == 0);
-    assert(bestShuffle("grrrrrr"d)[1] == 5);
-    assert(bestShuffle("seesaw"d)[1] == 0);
-    assert(bestShuffle("pop"d)[1] == 1);
-    assert(bestShuffle("up"d)[1] == 0);
-    assert(bestShuffle("a"d)[1] == 1);
-    assert(bestShuffle(""d)[1] == 0);
-}
-
-void main(string[] args) {
+void main(in string[] args) {
     if (args.length > 1) {
-        string entry = join(args[1 .. $], " ");
-        auto res = bestShuffle(entry);
-        writefln("%s : %s (%s)", entry, res[0], res[1]);
+        immutable entry = args.dropOne.join(" ");
+        const res = entry.bestShuffle;
+        writefln("%s : %s (%d)", entry, res[]);
     }
 }

Task/Best-shuffle/Perl/best-shuffle-1.pl

@@ -0,0 +1,28 @@
+use strict;
+use warnings;
+use List::Util qw(shuffle);
+use Algorithm::Permute;
+
+best_shuffle($_) for qw(abracadabra seesaw elk grrrrrr up a);
+
+sub best_shuffle {
+	my ($original_word) = @_;
+	my $best_word = $original_word;
+	my $best_score = length $best_word;
+
+	my @shuffled = shuffle split //, $original_word;
+	my $iterator = Algorithm::Permute->new(\@shuffled);
+	
+	while( my @array = $iterator->next ) {
+		my $word = join '', @array;
+		# For each letter which is the same in the two words,
+		# there will be a \x00 in the "^" of the two words.
+		# The tr operator is then used to count the "\x00"s.
+		my $score = ($original_word ^ $word) =~ tr/\x00//;
+		next if $score >= $best_score;
+		($best_word, $best_score) = ($word, $score);
+		last if $score == 0;
+	}
+	
+	print "$original_word, $best_word, $best_score\n";
+}

Task/Best-shuffle/Perl/best-shuffle-2.pl

@@ -0,0 +1,27 @@
+use strict;
+use warnings;
+use List::Util qw(shuffle);
+
+best_shuffle($_) for qw(abracadabra seesaw elk grrrrrr up a);
+
+sub best_shuffle {
+	my ($original_word) = @_;
+
+	my @s = split //, $original_word;
+	my @t = shuffle @s;
+
+	for my $i ( 0 .. $#s ) {
+		for my $j ( 0 .. $#s ) {
+			next if $j == $i or
+				$t[$i] eq $s[$j] or
+				$t[$j] eq $s[$i];
+			@t[$i,$j] = @t[$j,$i];
+			last;
+		}
+	}
+	
+	my $word = join '', @t;
+
+	my $score = ($original_word ^ $word) =~ tr/\x00//;
+	print "$original_word, $word, $score\n";
+}

Task/Best-shuffle/Perl/best-shuffle.pl

@@ -1,38 +0,0 @@
-use strict;
-use Algorithm::Permute;
-
-foreach ("abracadabra", "seesaw", "elk", "grrrrrr", "up", "a") {
-    best_shuffle($_);
-}
-
-sub score {
-    my ($original_word,$new_word) = @_;
-    my $result = 0;
-    for (my $i = 0 ; $i < length($original_word) ; $i++) {
-        if (substr($original_word,$i,1) eq substr($new_word,$i,1)) {
-            $result++;
-        }
-    }
-    return $result;
-}
-
-sub best_shuffle {
-    my ($original_word) = @_;
-    my $best_word = $original_word;
-    my $best_score = length($original_word);
-    my @array = split(//,$original_word);
-
-    # The below was adapted from perlfaq4
-
-    my $p_iterator = Algorithm::Permute->new( \@array );
-
-    while (my @array = $p_iterator->next) {
-        if (score($original_word,join("",@array))<$best_score) {
-            $best_score = score($original_word, join("",@array));
-            $best_word = join ("",@array);
-        }
-        last if ($best_score == 0);
-    }
-
-    print "$original_word, $best_word, $best_score\n";
-}

Task/Best-shuffle/Python/best-shuffle-1.py

@@ -1,4 +1,3 @@
-from collections import Counter
 import random
 
 def count(w1,wnew):
@@ -15,6 +14,7 @@ def best_shuffle(w):
         for j in rangej:
             if i != j and wnew[j] != wnew[i] and w[i] != wnew[j] and w[j] != wnew[i]:
                 wnew[j], wnew[i] = wnew[i], wnew[j]
+                break
     wnew = ''.join(wnew)
     return wnew, count(w, wnew)