problem-8.clj

(def number 
  (seq 
	(str "73167176531330624919225119674426574742355349194934"
		"96983520312774506326239578318016984801869478851843"
		"85861560789112949495459501737958331952853208805511"
		"12540698747158523863050715693290963295227443043557"
		"66896648950445244523161731856403098711121722383113"
		"62229893423380308135336276614282806444486645238749"
		"30358907296290491560440772390713810515859307960866"
		"70172427121883998797908792274921901699720888093776"
		"65727333001053367881220235421809751254540594752243"
		"52584907711670556013604839586446706324415722155397"
		"53697817977846174064955149290862569321978468622482"
		"83972241375657056057490261407972968652414535100474"
		"82166370484403199890008895243450658541227588666881"
		"16427171479924442928230863465674813919123162824586"
		"17866458359124566529476545682848912883142607690042"
		"24219022671055626321111109370544217506941658960408"
		"07198403850962455444362981230987879927244284909188"
		"84580156166097919133875499200524063689912560717606"
		"05886116467109405077541002256983155200055935729725"
		"71636269561882670428252483600823257530420752963450")))
		
(defn new-int [^String x] 
	(Integer. x))

(defn compute-product [x]
	(loop [y 0
		   product '()]
		(if (< y 5)
			(recur 
				(inc y) 
				(conj 
					product 
					(new-int (str (nth number (+ y x))))))
			(reduce * product))))
	

(defn find-it []
	(loop [x 0 largest 0]
		(let [product (compute-product x)]
			(if (>= x (- (count number) 5))
				largest
				(if (> product largest) 
					(recur (inc x) product)
					(recur (inc x) largest))))))