Project Euler Problem 8

Problem008.clj

;;; Find the greatest product of five consecutive digits in the 1000-digit number.
;;; problem8.txt に問題の数値を格納。

;;; 問題の数値文字列
(def problem8-str (apply str (re-seq #"\d+[^\n]" (slurp "src/sandbox/problem008.txt"))))
;;;=> "731671765313....63450"
(count problem8-str)
;;;=> 1000
(defn cut-nth [n] (Integer/parseInt (str (nth problem8-str n))))
(apply max (map #(* (cut-nth (+ 0 %))
                    (cut-nth (+ 1 %))
                    (cut-nth (+ 2 %))
                    (cut-nth (+ 3 %))
                    (cut-nth (+ 4 %)))
                (take (- 1000 5) (iterate inc 0))))
;;;=>result

problem008.txt

73167176531330624919225119674426574742355349194934
96983520312774506326239578318016984801869478851843
85861560789112949495459501737958331952853208805511
12540698747158523863050715693290963295227443043557
66896648950445244523161731856403098711121722383113
62229893423380308135336276614282806444486645238749
30358907296290491560440772390713810515859307960866
70172427121883998797908792274921901699720888093776
65727333001053367881220235421809751254540594752243
52584907711670556013604839586446706324415722155397
53697817977846174064955149290862569321978468622482
83972241375657056057490261407972968652414535100474
82166370484403199890008895243450658541227588666881
16427171479924442928230863465674813919123162824586
17866458359124566529476545682848912883142607690042
24219022671055626321111109370544217506941658960408
07198403850962455444362981230987879927244284909188
84580156166097919133875499200524063689912560717606
05886116467109405077541002256983155200055935729725
71636269561882670428252483600823257530420752963450