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15 lines
404 B
Plaintext
15 lines
404 B
Plaintext
(defn sum3
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"Solve the 3SUM problem O(n^2) time."
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[s]
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(def tab @{})
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(def solutions @{})
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(def len (length s))
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(for [k 0 len]
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(put tab (get s k) k))
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(for [i 0 len]
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(for [j 0 len]
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(def k (get tab (- 0 (get s i) (get s j))))
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(when (and k (not= k i) (not= k j) (not= i j))
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(put solutions {i true j true k true} true))))
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(iter2array (map (fn [x] (iter2array (keys x))) (keys solutions))))
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