["i", "love", "leetcode", "i", "love", "coding"], k = 2
输出: ["i", "love"]
解析: "i" 和 "love" 为出现次数最多的两个单词...sunny", "is", "is"], k = 4
输出: ["the", "is", "sunny", "day"]
解析: "the", "is", "sunny" 和 "day" 是出现次数最多的四个单词...(最小的栈顶)
5 开一ArrayList来存key
6 用Collections.sort(XX,new comparator) 来进行从大到小排序, (重写 比较器)
7 返回 Arraylist...for(String word:map.keySet()){
minQueue.add(word);
//如果size超过K,弹出堆首的数,因为最后要返回...size=k的list
if(minQueue.size()>k){
minQueue.poll();
}
}