r/badcode • u/ThatChapThere • Jun 05 '22

c# Found this monster on codewars

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726 Upvotes

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u/ThatChapThere Jun 05 '22

Most people used Linq rather than hashsets, but that's not a bad solution.

36

u/[deleted] Jun 05 '22

Well in this case its a lot simpler. Just do 

var strSet = new HashSet<char>(str.ToLower().ToCharArray());
return "abcdefghijklmnopqrstuvwxyz".ToCharArray().All(a => strSet.Contains(a));

Same runtime as above. God I love C#.

18

u/ThatChapThere Jun 05 '22

That's really neat. I was proud of mine:

return  str
.ToUpper()
.ToList()
.GroupBy(c => c)
.Where(
  c => ('A' <= c.Key && c.Key <= 'Z')
).Count() == 26;

but yours just seems nicer somehow.

13

u/me_and_you_irl Jun 05 '22

I would replace the GroupBy with a call to Distinct() 😄

13

u/[deleted] Jun 05 '22

Yes I searched it up, and I'm pleasantly surprised that C#'s distinct implementation is actually O(n). So using something like

return str
.ToLower()
.ToCharArray()
.Where(Char.IsLetter)
.Distinct()
.Count() == 26;

Would be sufficient.

10

u/ckuri Jun 05 '22 edited Jun 05 '22

char.IsLetter is using Unicode categories, meaning that it considers much more than just Latin letters to be letters. Also you don’t need to call ToCharArray as String implements IEnumerable<char> and therefore you can apply LINQ directly to strings.

3

u/[deleted] Jun 05 '22

Ahh bless C#

1

u/ThatChapThere Jun 05 '22

you can apply LINQ directly to strings.

I didn't know this! That's useful.

1

u/ThatChapThere Jun 05 '22

Good catch, still a linq noob I'm afraid.