Longest Consecutive Sequence

• Store all items in a hash set
• Go through each item in the hash set
• If the item is the begining of a sequence
• look for remaining items

def longest(nums):
    items = set(nums)
    maxsize = 0

    for item in items:
        if (item - 1) not in items:
            length = 1
            while (current + length) in items:
                length += 1
            maxsize = max(maxsize, length)

    return maxsize


def pr(ok): print("Ok" if ok else "Error")


pr(4 == longest([100, 4, 200, 1, 3, 2]))
pr(9 == longest([0, 3, 7, 2, 5, 8, 4, 6, 0, 1]))