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| -rw-r--r-- | challenge-117/james-smith/README.md | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/challenge-117/james-smith/README.md b/challenge-117/james-smith/README.md index 07571f0918..e17e38bcbc 100644 --- a/challenge-117/james-smith/README.md +++ b/challenge-117/james-smith/README.md @@ -53,7 +53,10 @@ sub triangle { } ``` -### Now the counts... Schroder numbers +Note we don't "collect" routes in a datastructure and then print them all at the end, but instead render directly from within the +function. For `$N` larger than `10` the memory requirements for storing this information increases significantly, so this code is limited purely by disk rather than memory. + +### Now the counts... Schröder numbers *It's amazing what you find out about when you google the answers you get!* @@ -99,8 +102,9 @@ sub schroder_non_recursive { We again use the row "flip" as we only need one row and the previous one to get values... -There is a faster solution - in that the Scrhoder numbers can be -written as a recurrence relation: +Googling for `2, 6, 22, 90, 394` came up with https://en.wikipedia.org/wiki/Schröder_number, a page +about Schröder numbers - which gives up the following faster (about twice as fast as above) solution - +as Scrhoder numbers can be written as a recurrence relation: ```perl sub schroder_recurrence_rel { |