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Submission #4147694

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```{-# LANGUAGE BangPatterns #-}
import Data.Int (Int64)
import qualified Data.Vector.Unboxed as V
import Data.List (foldl',tails)

modulo = 1000000007 :: Int64
addMod x y = (x + y) `mod` modulo
mulMod x y = (x * y) `mod` modulo

-- 多項式は
--   V.fromList [a,b,c,...,z] = a + b * X + c * X^2 + ... + z * X^(k-1)
-- により表す。

-- 多項式を X^k - X^(k-1) - ... - X - 1 で割った余りを返す。
reduce :: Int -> V.Vector Int64 -> V.Vector Int64
reduce k v | V.last v == 0 = V.init v
| V.length v <= k = v
| otherwise = let b = V.last v
l = V.length v
in reduce k (V.imap (\i a -> if i >= l - k - 1 then a `addMod` b else a) (V.init v))

-- 多項式の積を X^k - X^(k-1) - ... - X - 1 で割った余りを返す。
mulP :: Int -> V.Vector Int64 -> V.Vector Int64 -> V.Vector Int64
mulP k !v !w = reduce k \$ V.generate (V.length v + V.length w - 1) \$
\i -> sumMod [(v V.! (i-j)) `mulMod` (w V.! j) | j <- [0..V.length w-1], j <= i, j > i - V.length v]

-- 不定元
ind :: V.Vector Int64
ind = V.fromList [0,1]

-- 多項式の（mod X^k - X^(k-1) - ... - X - 1 での）べき乗
powP :: Int -> V.Vector Int64 -> Int -> V.Vector Int64
powP k _ 0 = V.fromList [1]
powP k m i = loop (i-1) m m
where
loop 0 !_ !acc = acc
loop 1 m acc = mulP k m acc
loop i m acc = case i `quotRem` 2 of
(j,0) -> loop j (mulP k m m) acc
(j,_) -> loop j (mulP k m m) (mulP k acc m)

main :: IO ()
main = do
l <- getLine
if n <= k
then print 1
else do
let f = powP k ind (n - k) -- X^(n-k) mod X^k - X^(k-1) - ... - X - 1
let seq = replicate k 1 ++ map (sumMod . take k) (tails seq) -- 数列
print \$ sumMod \$ zipWith mulMod (V.toList f) (drop (k-1) seq)
```

#### Submission Info

Submission Time 2019-02-03 02:16:11+0900 T - フィボナッチ mod_poppo Haskell (GHC 7.10.3) 8 1984 Byte AC 1759 ms 2172 KB

#### Judge Result

Set Name All
Score / Max Score 8 / 8
Status
 AC × 7
Set Name Test Cases
All 00, 01, 02, 03, 04, 90, 91
Case Name Status Exec Time Memory
00 AC 1724 ms 2172 KB
01 AC 951 ms 1916 KB
02 AC 1759 ms 2172 KB
03 AC 294 ms 1916 KB
04 AC 2 ms 508 KB
90 AC 2 ms 508 KB
91 AC 2 ms 508 KB