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14 lines
364 B
Plaintext
14 lines
364 B
Plaintext
(defn sum3
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"Solve the 3SUM problem in 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 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 s@i 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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(map keys (keys solution))) |