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maarek/gist:ecbe1e176c292b6912be

Last active August 29, 2015 14:15
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Length of longest subsequence of (+1)-increasing consecutive integers
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gistfile1.clj
; ex. (= (__ [1 0 1 2 3 0 4 5]) [0 1 2 3])
; #1 given list
(def lci (fn [list]
; #2 create partitioned list ((1 0) (0 1) (1 2) (2 3) (3 0) (0 4) (4 5))
; #3 perform last first on partitioned list
(->> (partition 2 1 list)
; #4 goes through each group and determines if index 2 is less than index 1 and groups those as it iterates
; (((1 0)) ((0 1) (1 2) (2 3)) ((3 0)) ((0 4)) ((4 5)))
(partition-by #(- (second %) (first %)))
; #5 iterate each group from the previous to determine is index 2 is less than 1 and if true return
; #6 (((0 1) (1 2) (2 3)) ((4 5)))
(filter #(= 1 (- (second (first %)) (ffirst %))))
; #7 check each group if on which has greater count and return that one ((0 1) (1 2) (2 3))
(reduce #(if (< (count %1) (count %2)) %2 %1) [])
; #8 flatten all values back into one list (0 1 1 2 2 3)
flatten
; #9 remove copies that were created by the grouping
distinct
; #10 count
count
)
))
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