diff options
| -rw-r--r-- | challenge-111/james-smith/perl/ch-1.pl | 35 |
1 files changed, 25 insertions, 10 deletions
diff --git a/challenge-111/james-smith/perl/ch-1.pl b/challenge-111/james-smith/perl/ch-1.pl index d4cab57a2c..a0d65cc263 100644 --- a/challenge-111/james-smith/perl/ch-1.pl +++ b/challenge-111/james-smith/perl/ch-1.pl @@ -16,30 +16,45 @@ my $matrix = [ ## Create a test set - numbers from -10 to 60... my %TEST_SET = map { $_ => 0 } (-10..60); -## Set all to 0 and then set all in matrix to 1 + +## Set all to 0, and then iterate through the +## elements of the matrix and set the numbers +## in the list to 1.... + $TEST_SET{$_} = 1 foreach map { @{$_} } @{$matrix}; +## Run the original PWC test examples... is( find_val( 35, $matrix ), 0 ); is( find_val( 39, $matrix ), 1 ); -is( find_val( 3, $matrix ), 1 ); -is( find_val( 8, $matrix ), 0 ); -is( find_val( 23, $matrix ), 1 ); -is( find_val( 41, $matrix ), 0 ); -## Full test set! Try all numbers from -10 to 60 -## { either side of the list! } +## Now run our full test set - from -10 to 60. This covers +## all cases within the list and a few either side... + is( find_val( $_, $matrix ), $TEST_SET{$_} ) foreach sort {$a<=>$b} keys %TEST_SET; done_testing(); sub find_val { + ## Flatten the array provided into a list... my( $val, $m, @list ) = ( $_[0], 0, map { @{$_} } @{$_[1]} ); - $list[ $m = @list >> 1 ] == $val ? ( return 1 ) - : $list[ $m ] > $val ? ( splice @list, $m ) - : ( splice @list, 0, $m ) + ## We trim the list depending on the value of the middle point + ## If it matches we return 1 o/w we throw the middle value and + ## the other half of the list - by using splice... + + $list[ $m = @list >> 1 ] == $val ? ( return 1 ) + : $list[ $m ] > $val ? ( splice @list, $m ) + : ( splice @list, 0, $m+1 ) while @list>1; + + ## We stop when we get to a list of either 0 or 1 entries. + ## If the list has length 0 then we return 0 + ## If it has one element we return whether or not it is the value + return @list && $list[0] == $val ? 1 : 0; + + ## The latter occurs when the true value happens at the start of + ## list either at initially or after one of the splices... } |