最常使用的K个单词II|最常使用的K个单词II · Top K Frequent Words II 最常使用的K个单词II·TopKFreq

import java.util.NavigableSet;
public class TopK {
private Map words = null;
private NavigableSet topk = null;
private int k;

private Comparator myComparator = new Comparator() { public int compare(String left, String right) { if (left.equals(right)) return 0; int left_count = words.get(left); int right_count = words.get(right); if (left_count != right_count) { return right_count - left_count; } return left.compareTo(right); } }; public TopK(int k) { // initialize your data structure here this.k = k; words = new HashMap(); topk = new TreeSet(myComparator); }public void add(String word) { // Write your code here if (words.containsKey(word)) { if (topk.contains(word)) topk.remove(word); words.put(word, words.get(word) + 1); } else { words.put(word, 1); }topk.add(word); if (topk.size() > k) { topk.pollLast(); } }public List topk() { // Write your code here List results = new ArrayList(); Iterator it = topk.iterator(); while(it.hasNext()) { String str = (String)it.next(); results.add(str); } return results; }

【最常使用的K个单词II|最常使用的K个单词II · Top K Frequent Words II】}