Triangle Minimal Path

gistfile1.clj

(fn min-path- [triangle]
  ^{:doc "79. Write a function which calculates the sum of the minimal
  path through a triangle."}
  ;; We're going to use a dynamic programming solution, which will
  ;; reduce from the bottom of the triangle upward, replacing each row
  ;; with the sum from there on down. After the final reduction the
  ;; single remaining row will contain one element with the sum of the
  ;; min path.
  (loop [r (reverse triangle)]
    (if (= 1 (count r))
      (ffirst r)
      (recur (cons
              (map min
                   (map + (second r) (butlast (first r)))
                   (map + (second r) (rest (first r))))
              (drop 2 r))))))