presents.clj

(use 'clojure.java.io)

(def ribbon (atom 0))
(def paper (atom 0))

(with-open [rdr (reader "./presents.txt")]
  (doseq [line (line-seq rdr)]
    (let [all (clojure.string/split line #"x")
          w (. Integer parseInt (first all))
          h (. Integer parseInt (second all))
          l (. Integer parseInt (nth all 2))
          side1 (* w h)
          side2 (* w l)
          side3 (* h l)
          area (* w h l)
          surface-area (* 2 (+ side1 side2 side3))
          min-side (min side1 side2 side3)
          paper-for-box (+ min-side surface-area)
          min-circ (* 2 (min (+ w h)
                             (+ w l)
                             (+ h l)))
          ribbon-for-box (+ area min-circ)]
                           
      (swap! paper +  paper-for-box)
      (swap! ribbon + ribbon-for-box))))

(printf "ribbon is %s%n" @ribbon) 
(printf "paper yardage is %s%n " @paper)