Merge pull request #6928 from drbaggy/master

Neater more compact solution..

2 files changed, 22 insertions, 8 deletions

diff --git a/challenge-187/james-smith/README.md b/challenge-187/james-smith/README.md
index b1fbbf2150..6779522e79 100644
--- a/challenge-187/james-smith/README.md
+++ b/challenge-187/james-smith/README.md
@@ -92,21 +92,24 @@ This is a permutation challenge, so we loop through the values with 3 nested loo
 
 By sorting we can make the assumption that `$a,$b,$c` are automatically sorted highest to lowest..
 
+This has two advantages:
+ 1. The results will always be sorted `$a>=$b>=$c`
+ 2. The 3 inequalities can reduce to a single inequality - all three are satisfied if `$b+$c > $a`, as this is the smallest sum of two numbers and the largest single number;
+ 3. The first solution we find will have the largest sum of `$a+$b+$c` so we don't need to keep track of the maximum solution - but return the first we can find...
+
 Each time through we use shift to get the first element of each loop until there are no values left. Note in this case we use `while` for the outer two loops...
 
 ```perl
 sub magical {
   @_ = sort { $b <=> $a } @_;
-  my @max = (0);
   while(@_>2) {
     my($a,$b,@c)=@_;
     while(@c) {
-      ($a+$b>$_) && ($b+$_>$a) && ($a+$_>$b) && ($a+$b+$_>$max[0]) && (@max=($a+$b+$_,$a,$b,$_)) for @c;
+      ( $b+$_ > $a ) && ( return $a,$b,$_ ) for @c;
       $b = shift @c;
     }
     shift;
   }
-  shift @max;
-  @max;
+  ();
 }
 ```
diff --git a/challenge-187/james-smith/perl/ch-2.pl b/challenge-187/james-smith/perl/ch-2.pl
index e08218ad26..e7c46dd075 100644
--- a/challenge-187/james-smith/perl/ch-2.pl
+++ b/challenge-187/james-smith/perl/ch-2.pl
@@ -13,24 +13,35 @@ my @TESTS = (
   [ [1,3,2],   '' ],
   [ [1,1,2,3], '' ],
   [ [2,4,3],   '4 3 2' ],
+  [ [1..10],   '10 9 8' ],
+  [ [7,4,1],  '' ],
+  [ [201,101,1],  '' ],
+  [ [1,1,2,3,4,5,2,1,2,3,2,1,1,1,1,1], '5 4 3' ],
 );
 
+for( 1..100 ) {
+  my @T = map { 1 + int rand 20 } 1 .. 3 + int rand 17;
+  my $r = join ' ', (sort {$b<=>$a} @T)[0,1,2];
+  push @TESTS, [ \@T, $r ]
+}
+
+
 is( "@{[magical(@{$_->[0]})]}", $_->[1] ) foreach @TESTS;
 
 done_testing();
 
 sub magical {
   @_ = sort { $b <=> $a } @_;
-  my @max = (0);
   while(@_>2) {
     my($a,$b,@c)=@_;
     while(@c) {
-      ($a+$b>$_) && ($b+$_>$a) && ($a+$_>$b) && ($a+$b+$_>$max[0]) && (@max=($a+$b+$_,$a,$b,$_)) for @c;
+      ($b+$_>$a) && (return $a,$b,$_ ) for @c;
       $b = shift @c;
     }
     shift;
   }
-  shift @max;
-  @max;
+  ();
+  #shift @max;
+  #@max;
 }