Solución Calculando Capicuas de Programando.org en Clojure

part2.clj

(ns capicuas.part2)

(defn reverso [res n]
  (if (zero? n)
    res
    (recur (+' (* 10 res) (rem n 10)) (quot n 10))))

(defn not-palin? [n]
  (not= n (reverso 0 n)))

(defn next-capicua [n]
  (+' n (reverso 0 n)))

(defn iters-capicua [n]
  (let [[its caps] (->> (iterate next-capicua n)
                        rest
                        (take 1000) ;; max numero de iteraciones
                        (split-with not-palin?))]
    (if (first caps)
      (inc (count its))
      0)))

;; Tests:
;; (iters-capicua 57) ;; => 2
;; (iters-capicua 43) ;; => 1
;; (iters-capicua 77) ;; => 3

;; Solucion:
;; (apply max-key iters-capicua (range 100 1001)) ;; => 880
;; (iters-capicua 880) ;; => 23
;; (->> (iterate next-capicua 880) (drop-while not-palin?) first) ;; => 8813200023188