Determining if an array has a k-majority element

Question

Suppose that, given an n-element multiset A (not sorted), we want an O(n) time algorithm for determining whether A contains a majority element, i.e., an element that occurs

Answer 1

I don't know if you've seen this one, but it may help to give you ideas:

Suppose you know there is a majority element in an array L.

One way to find the element is as follows:

Def FindMajorityElement(L):

    Count = 0

    Foreach X in L

        If Count == 0
            Y = X

        If X == Y
            Count = Count + 1
        Else
            Count = Count - 1

    Return Y

O(n) time, O(1) space