Hackerrank Count Swaps

Challenge

Prit’s solution

(defn count-swaps [a]
  (letfn [(swap [a i j] ;; looked up letfn online
            (assoc a i (nth a j) j (nth a i)))]
    (loop [a a num-swaps 0 i 0]
      (if (< i (count a))
        (let [int-loop (loop [a' a j 0 num-swaps' 0]
                         (if (< j (dec (count a)))
                           (if (> (nth a j) (nth a (inc j)))
                             (recur (swap a' j (inc j)) (inc j) (inc num-swaps'))
                             (recur a' (inc j) num-swaps'))
                           [a' num-swaps']))]
          (recur (nth int-loop 0) (+ num-swaps (nth int-loop 1)) (inc i)))
        [num-swaps (nth a 0) (nth a (dec (count a)))]))))

(let [result (count-swaps [4 2 3 1])]
  (prn (str "Array is sorted in " (nth result 0) " swaps.") )
  (prn (str "First Element: " (nth result 1)) )
  (prn (str "Last Element: " (nth result 2)))
  )

I make a nested loop-recur one for iterating through the i index and one for iterating through the j index.