4clojure 题解 Nth Element

模拟nth函数

Write a function which returns the Nth element from a sequence.

	(= (__ '(4 5 6 7) 2) 6)
	(= (__ [:a :b :c] 0) :a)
	(= (__ [1 2 3 4] 1) 2)
	(= (__ '([1 2] [3 4] [5 6]) 2) [5 6])

用递归试了下可以通过

(fn d [seq x]
   (if (> x 0)
     (d (rest seq) (dec x))
     (first seq)))