/**
	 * 找出兩個數組相同的元素，並且對應的個數一樣
	 * @param args
	 */
	public static void getSameNumberCount(String[] a, String[] b) {
		Map<String, Integer> map = new HashMap<String, Integer>();
		for (int i = 0; i < a.length; i++) {
			if (!map.containsKey(a[i])) {
				map.put(a[i], 1);
			} else {
				map.put(a[i], map.get(a[i]) + 1);
			}
		}
		
		for (int j = 0; j < b.length; j++) {
			if (map.containsKey(b[j])) {
				System.out.println(b[j]);
				if (map.get(b[j]) > 1) {
					map.put(b[j], map.get(b[j]) - 1);
				} else {
					map.remove(b[j]);
				}
			}
		}
	}
	
	
	public static void main(String[] args) {
		String[] x = {"a","b","c","d"};
		String[] y = {"a","a","b","b","c"};
		getSameNumberCount(y, x);
	}

找出兩個數組相同的元素，並且對應的個數一樣