In python, how does one efficiently find the largest consecutive set of numbers in a list that are not necessarily adjacent?

Question

For instance, if I have a list

[1,4,2,3,5,4,5,6,7,8,1,3,4,5,9,10,11]

This algorithm should return [1,2,3,4,5,6,7,8,9,10,11].

To cl

Answer 1

Warning: This is the cheaty way to do it (aka I use python...)

import operator as op
import itertools as it

def longestSequence(data):

    longest = []

    for k, g in it.groupby(enumerate(set(data)), lambda(i, y):i-y):
        thisGroup = map(op.itemgetter(1), g)

        if len(thisGroup) > len(longest):
            longest = thisGroup

    return longest


longestSequence([1,4,2,3,5,4,5,6,7,8,1,3,4,5,9,10,11, 15,15,16,17,25])