day11.clj

(defn power
  [serial x y]

  (let [
        rack-id (+ x 10)
        ]

    (-
     (Math/floor
      (mod
       (/ (* (+ (* rack-id y) serial) rack-id) 100)
       10))
     5)))

(defn sum-square
  [square]
  (reduce + 0 (map (partial apply power) square)))

(defn max-with-size
  [serial size]
  (apply max-key
         sum-square
         (for [
               x (range 1 301)
               y (range 1 301)
               ]

           (for [xx (range x (+ x size))
                 yy (range y (+ y size))
                 ]
             [serial xx yy]))))