Code Jam Japan Problem B

gcjj_pB.clj

(require '[clojure.contrib.io :as io])

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Main funcs

;; sort coffee data by
;;  : in descending order with satisfaction
;;  : and in accending order with expiry date.

(defn sort-coffee-data [dat-list]
  (sort (fn [d1 d2]
	  (cond (> (last d1) (last d2)) -1
		(< (last d1) (last d2)) 1
		:else (if (< (second d1) (second d2)) -1 1)))
	dat-list))

(defn asign-coffee [coffee-dat K]
  (let [[num due wgt] coffee-dat
	P (if (> due K) K due)
	n (if (> num P) P num)]
    [(* wgt n) P n]))

(defn update-coffee-list [coffee-list P n]
  (map (fn [[num due wgt]]
	 [num
	  (cond (> due P) (- due n)
		(> due (- P n)) (- P n)
		:else due)
	  wgt])
       coffee-list))



(defn gcj-pB [key-arg coffee-list]
  (let [[_ K] key-arg]
    (loop [coffee-list (sort-coffee-data coffee-list)
	   total-days K
	   s-total 0]
      (if (empty? coffee-list)
	s-total
	(let [[s-amount P n] (asign-coffee (first coffee-list) K)]
	  (recur (update-coffee-list (next coffee-list) P n)
		 (- K n)
		 (+ s-total s-amount)))))))


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;; Support funcs 

;; get args from the question file.
;; returns them as 
;;      ((1 ((N K) ((c1 t1 s1)(c1 t1 s12)...))) (2 ........))

(defn get-gcj-args-list-pB [file-name]
  (let [tmptmp
	(reduce (fn [[tmp-dat res] dat]
		  (cond (= (count dat) 2) [[dat []] (conj res tmp-dat)]
			(= (count dat) 3) [[(first tmp-dat) (vec (conj (second tmp-dat) dat))] res]
			:final  (vec (conj (second tmp-dat) dat))))
		[[] []]
		(map (fn [line-dat]
		       (map (fn [s] (BigInteger. s))
			    (.split line-dat " ")))
		     (drop 1 (io/read-lines file-name))))]
    (map list
	 (iterate inc 1)
	 (conj (vec (drop 1 (second tmptmp))) (first tmptmp)))))

(defn gcj-get-ans-pB [file-name f]
  (map (fn [[num args]] [num (apply f args)]) 
	(get-gcj-args-list-pB file-name)))

(defn gcj-create-ans-pB [in-file out-file f]
    (with-open [bw (io/writer out-file)]
      (io/with-out-writer bw
	(dorun
	 (for [[num ans] (gcj-get-ans-pB in-file f)]
	   (println (str "Case #" num ": " ans)))))))

;; (time (gcj-create-ans-pB "B-large-practice.in" "B-large-practice.out" gcj-pB))
;; time for large
;; "Elapsed time: 535.676461 msecs"