comment

glguy · Dec 9, 2023 · 1c72106 · 1c72106
1 parent f4eaea1
commit 1c72106
Showing 1 changed file with 4 additions and 3 deletions.
diff --git a/solutions/src/2023/09.hs b/solutions/src/2023/09.hs
@@ -9,7 +9,8 @@ Maintainer  : emertens@gmail.com
 
 <https://adventofcode.com/2023/day/9>
 
-Extend an 
+Interpolate a polynomial sequence to find the next and previous
+elements of the sequence.
 
 >>> :{
 :main +
@@ -22,7 +23,7 @@ Extend an
 2
 
 -}
-module Main where
+module Main (main) where
 
 import Advent (format)
 
@@ -41,4 +42,4 @@ nextInSequence :: [Int] -> Int
 nextInSequence = sum . map last . takeWhile (any (0 /=)) . iterate differences
 
 differences :: [Int] -> [Int]
-differences xs = zipWith subtract xs (tail xs)
+differences xs = zipWith subtract xs (tail xs)