1348. Tweet Counts Per Frequency
Medium
Implement the class TweetCounts
that supports two methods:
1. recordTweet(string tweetName, int time)
- Stores the
tweetName
at the recordedtime
(in seconds).
2. getTweetCountsPerFrequency(string freq, string tweetName, int startTime, int endTime)
- Returns the total number of occurrences for the given
tweetName
per minute, hour, or day (depending onfreq
) starting from thestartTime
(in seconds) and ending at theendTime
(in seconds). freq
is always minute, hour or day, representing the time interval to get the total number of occurrences for the giventweetName
.- The first time interval always starts from the
startTime
, so the time intervals are[startTime, startTime + delta*1>, [startTime + delta*1, startTime + delta*2>, [startTime + delta*2, startTime + delta*3>, ... , [startTime + delta*i, min(startTime + delta*(i+1), endTime + 1)>
for some non-negative numberi
anddelta
(which depends onfreq
).
Example:
Input ["TweetCounts","recordTweet","recordTweet","recordTweet","getTweetCountsPerFrequency","getTweetCountsPerFrequency","recordTweet","getTweetCountsPerFrequency"] [[],["tweet3",0],["tweet3",60],["tweet3",10],["minute","tweet3",0,59],["minute","tweet3",0,60],["tweet3",120],["hour","tweet3",0,210]] Output [null,null,null,null,[2],[2,1],null,[4]] Explanation TweetCounts tweetCounts = new TweetCounts(); tweetCounts.recordTweet("tweet3", 0); tweetCounts.recordTweet("tweet3", 60); tweetCounts.recordTweet("tweet3", 10); // All tweets correspond to "tweet3" with recorded times at 0, 10 and 60. tweetCounts.getTweetCountsPerFrequency("minute", "tweet3", 0, 59); // return [2]. The frequency is per minute (60 seconds), so there is one interval of time: 1) [0, 60> - > 2 tweets. tweetCounts.getTweetCountsPerFrequency("minute", "tweet3", 0, 60); // return [2, 1]. The frequency is per minute (60 seconds), so there are two intervals of time: 1) [0, 60> - > 2 tweets, and 2) [60,61> - > 1 tweet. tweetCounts.recordTweet("tweet3", 120); // All tweets correspond to "tweet3" with recorded times at 0, 10, 60 and 120. tweetCounts.getTweetCountsPerFrequency("hour", "tweet3", 0, 210); // return [4]. The frequency is per hour (3600 seconds), so there is one interval of time: 1) [0, 211> - > 4 tweets.
Constraints:
- There will be at most
10000
operations considering bothrecordTweet
andgetTweetCountsPerFrequency
. 0 <= time, startTime, endTime <= 10^9
0 <= endTime - startTime <= 10^4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 | class TweetCounts { Map<String, Integer> fMap = new HashMap<>(); Map<String, TreeMap<Integer, Integer>> map = new HashMap<>(); public TweetCounts() { fMap.put("minute", 60); fMap.put("hour", 60*60); fMap.put("day", 60*60*24); } public void recordTweet(String tweetName, int time) { if(!map.containsKey(tweetName)) map.put(tweetName, new TreeMap<>()); TreeMap<Integer, Integer> tMap = map.get(tweetName); tMap.put(time, tMap.getOrDefault(time, 0)+1); } void printMap(String name){ for(Map.Entry<Integer, Integer> en : map.get(name).entrySet()){ System.out.print(en.getKey()+"->"+en.getValue()+" "); } System.out.println(); } public List<Integer> getTweetCountsPerFrequency(String freq, String tweetName, int startTime, int endTime) { // printMap(tweetName); List<Integer> list = new ArrayList<>(); int d = fMap.get(freq); if(map.containsKey(tweetName)){ TreeMap<Integer, Integer> tMap = map.get(tweetName); int a = startTime; while(a<=endTime){ int b = a + d - 1; int r = 0; for(Map.Entry<Integer, Integer> en : map.get(tweetName).subMap(a, true, b, true).entrySet()){ r += en.getValue(); } list.add(r); a = b+1; } } return list; } } |
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