Problem statement:
Given an integer array of size n, find all elements that appear more than ⌊ n/3 ⌋ times. The algorithm should run in linear time and in O(1) space.
⌊ n/3 ⌋
Solution:
229. Majority Element II
原文：http://www.cnblogs.com/wdw828/p/6917176.html
