diff options
| -rw-r--r-- | challenge-152/james-smith/README.md | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/challenge-152/james-smith/README.md b/challenge-152/james-smith/README.md index 09f8ad0cb4..9aab95bd67 100644 --- a/challenge-152/james-smith/README.md +++ b/challenge-152/james-smith/README.md @@ -32,24 +32,22 @@ Each time through the loop we generate a new version of `@p` with the best route ```perl sub min_path { - my @p = map { [0,[]] } 0,my @t = reverse @{$_[0]}; - @p = map { $p[0][0] < $p[1][0] - ? [ $_+$p[0][0], [ $_, @{$p[0][1]} ] ] - : [ $_+$p[1][0], [ $_, @{$p[1][1]} ] ] - , (shift @p) x 0 - } @{$_} for @t; + my @p = ( [0,[]] ) x (1 + @{$_[0]}); + @p = map { $p[0][0] < $p[1][0] ? [ $_+$p[0][0], [ $_, @{$p[0][1]} ] ] : [ $_+$p[1][0], [ $_, @{$p[1][1]} ] ], (shift @p) x 0 } @{$_} for reverse @{$_[0]}; say sprintf 'Minimum value %d: [ %s ]', $p[0][0], join ', ', @{$p[0][1]}; $p[0][0]; } + ``` We can simplify this if we are not worried by the order - by storing a simple value (the minimum total for the path) rather than the pair total/path. ```perl sub min_path_total { - my @p = map { 0 } 0, my @t = reverse @{$_[0]}; - @p = map { $_ + $p[ $p[0] < $p[1] ? 0 : 1 ], (shift @p)x 0 } @{$_} for @t; + my @p = (0) x (1+@{$_[0]}); + @p = map { $_ + $p[$p[0]<$p[1]?0:1], (shift @p)x 0 } @{$_} for reverse @{$_[0]}; $p[0]; + } ``` |