Day 29: Count goodStrings #22
Open
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
jabagawee
reviewed
May 9, 2017
| constructing a good string, we should not place another letter 'a' in the same | ||
| good string. And likewise, we shouldn't place letters into the good string | ||
| if they are lexicographically less than the characters that precede it. | ||
|
|
There was a problem hiding this comment.
i think you misread the 3rd rule. note that it says "exactly one" and not "every"
jabagawee
reviewed
May 9, 2017
| return factorial(n) / (factorial(n-r) * factorial(r)) | ||
|
|
||
| def goodStringsCount(n): | ||
| return nChooseR(26, n) * (2**n - n - 1) |
There was a problem hiding this comment.
this solution works but it doesn't follow from the examples in your ideas section
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
rip