#171
Intervals
 

Difficulty:Medium
Topics:


Write a function that takes a sequence of integers and returns a sequence of "intervals". Each interval is a a vector of two integers, start and end, such that all integers between start and end (inclusive) are contained in the input sequence.
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(= (__ [1 2 3]) [[1 3]])
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(= (__ [10 9 8 1 2 3]) [[1 3] [8 10]])
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(= (__ [1 1 1 1 1 1 1]) [[1 1]])
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(= (__ []) [])
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(= (__ [19 4 17 1 3 10 2 13 13 2 16 4 2 15 13 9 6 14 2 11])
       [[1 4] [6 6] [9 11] [13 17] [19 19]])


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