(Array)169. Majority Element

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.

You may assume that the array is non-empty and the majority element always exist in the array.

public class Solution {      //更好的方法是排序，return 中间那个数
    public int majorityElement(int[] nums) {
     	Map<Integer, Integer> map = new HashMap<Integer, Integer>();
		for (int i = 0; i < nums.length; i++) {
			if (map.containsKey(nums[i])) {
				map.put(nums[i], map.get(nums[i])+1);
			} else
				map.put(nums[i], 1);
		}
		Set set = map.entrySet();
		Iterator it = set.iterator();
		int res = 0;
		while (it.hasNext()) {
			Map.Entry entry = (Map.Entry) it.next();
			if ((int) entry.getValue() > nums.length / 2)
				res = (int) entry.getKey();
		}
		return res;
    }
    
}