Elegant Project Euler Solution
rick.kreikebaum at gmail.com
Wed Nov 13 01:29:48 UTC 2019
Yeah, I know. I found it after I returned to this thread. It was
a bit confusing away from my computer cause I thought the OP must
have been using the permutations() function, and I was like "wait
a minute, how can that be correct when it doesn't generate them
in lexicographical order." When I checked it again, I saw he used
the nthPermutation() function and found it in the documentation.
I'll file a bug report when I get around to it.
When I solved Problem 24 myself a couple years ago, I wrote my
own spaghetti code algorithm for it, as follows:
Iterate backwards until you find the first item that's less than
Find the lowest item after that that's still greater than it
Swap the two
Sort the portion of the array after the index of the item in step
For some of the later problems, I just used the standard
library's nextPermutation() function. But now that I looked at my
old code again, I think I'm going to factor out my algorithm into
my own nextPermutation function with the same semantics as the
one in the standard library.
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