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.
第一种方法:
存到hashmap中，然后找出现次数多于一半的。
1 public class Solution { 2 public int majorityElement(int[] num) { 3 HashMap<Integer, Integer> map = new HashMap<Integer, Integer>(); 4 for(int n : num){ 5 if(map.containsKey(n)) map.put(n, map.get(n) + 1); 6 else map.put(n, 1); 7 } 8 for(int i : map.keySet()){ 9 if(map.get(i) > num.length / 2) return i; 10 } 11 return -1; 12 } 13 }
原文：http://www.cnblogs.com/reynold-lei/p/4226888.html