HashMap解法

import java.util.HashMap;
public class Solution {
    public int MoreThanHalfNum_Solution(int [] array) {
        if(array==null||array.length==0)return 0;
        HashMap<Integer,Integer> m = new HashMap<Integer,Integer>();
        for(int i=0;i<array.length;i++){
            if(!m.containsKey(array[i]))m.put(array[i],1);
            else m.put(array[i],m.get(array[i])+1);
        }
        //注意此处返回key
        for(int key: m.keySet()){
            if(m.get(key)>array.length/2)
               return key;
        }
        return 0;
    }
}