西宁网站建设君博推荐,建站模板更改,展厅设计素材网站,广州微型网站建设用链表存储用户发送的每一个推特#xff0c;用堆获取最先的10条动态
class Twitter {MapInteger,SetInteger followMap;//规定最新的放到最后MapInteger,Tweet postMap;//优先队列(堆#xff09;PriorityQueueTweet priorityQueue;int time…用链表存储用户发送的每一个推特用堆获取最先的10条动态
class Twitter {MapInteger,SetInteger followMap;//规定最新的放到最后MapInteger,Tweet postMap;//优先队列(堆PriorityQueueTweet priorityQueue;int timeStamp 0;int limit 10;public Twitter() {followMap new HashMap();postMap new HashMap();//按照每一个推特发送的时间戳由大到小排布priorityQueue new PriorityQueue((t1,t2) - t2.timeStamp - t1.timeStamp);}//userId发送推特public void postTweet(int userId, int tweetId) {//首先根据postMap来获取userId对应发送到文章Tweet tweet postMap.get(userId);//生成新的tweetTweet newTweet new Tweet(tweetId, timeStamp, tweet);postMap.put(userId,newTweet);}//根据userId获得自己和关注用户的10条推特按时间顺序由近到远排序public ListInteger getNewsFeed(int userId) {//因为每一个用户都有自己的优先队列所以先清空优先队列priorityQueue.clear();//将自己和关注的用户发送的最新的推特id先放入到优先队列if (postMap.containsKey(userId))priorityQueue.offer(postMap.get(userId));SetInteger follows followMap.get(userId);if (follows ! null){for (Integer follow : follows) {if (postMap.containsKey(follow))priorityQueue.offer(postMap.get(follow));}}//现在用户和所有关注的推特都已经放入到优先队列开始获取前10条int count 0;ArrayListInteger result new ArrayList();while (!priorityQueue.isEmpty() count limit){//获取头部,在优先队列中删除Tweet tweet priorityQueue.poll();result.add(tweet.id);if (tweet.next ! null)priorityQueue.offer(tweet.next);count;}return result;}//关注public void follow(int followerId, int followeeId) {// 被关注人不能是自己if (followeeId followerId) {return;}SetInteger follows followMap.getOrDefault(followerId, new HashSet());follows.add(followeeId);followMap.put(followerId,follows);}//取关public void unfollow(int followerId, int followeeId) {// 被关注人不能是自己if (followeeId followerId) {return;}SetInteger follows followMap.getOrDefault(followerId, new HashSet());follows.remove(followeeId);followMap.put(followerId,follows);}
}
class Tweet{int id;int timeStamp;Tweet next;public Tweet(int id, int timeStamp) {this.id id;this.timeStamp timeStamp;}public Tweet(int id, int timeStamp, Tweet next) {this.id id;this.timeStamp timeStamp;this.next next;}
}/*** Your Twitter object will be instantiated and called as such:* Twitter obj new Twitter();* obj.postTweet(userId,tweetId);* ListInteger param_2 obj.getNewsFeed(userId);* obj.follow(followerId,followeeId);* obj.unfollow(followerId,followeeId);*/
