janet/examples/3sum.dst

(defn sum3
 "Solve the 3SUM problem in O(n^2) time."
 [s]
 (def tab @{})
 (def solutions @{})
 (def len (length s))
 (loop [k :range [0 len]]
  (put tab (get s k) k))
 (loop [i :range [0 len], j :range [0 len]]
  (def k (get tab (- 0 (get s i) (get s j))))
  (when (and k (not= k i) (not= k j) (not= i j))
   (put solutions {i true j true k true} true)))
 (map keys (keys solution)))