mirror of
https://github.com/janet-lang/janet
synced 2024-11-18 14:44:48 +00:00
14 lines
401 B
Plaintext
14 lines
401 B
Plaintext
(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)))
|