TT1.java

importjava.util.*;

publicclassTT1 {
enumFrequency {
MINUTE, HOUR, DAY
 }

privateMap<String, TreeMap<Long, Integer>> tweets;

publicTT1() {
tweets = newHashMap<>();
 }

publicvoidrecordTweet(StringtweetName, longtime) {
tweets.putIfAbsent(tweetName, newTreeMap<>());
TreeMap<Long, Integer> times = tweets.get(tweetName);
times.put(time, times.getOrDefault(time, 0) + 1);
 }

publiclong[] getTweetCountsPerFrequency(Frequencyfreq, StringtweetName, longstartTime, longendTime) {
TreeMap<Long, Integer> times = tweets.get(tweetName);

longdiff = endTime - startTime;
longdelta = getDelta(freq);
long[] result = newlong[(int) (diff / delta) + 1];

longstartInterval = startTime, endInterval = startInterval + delta;
intidx = 0;

while (startInterval <= endTime) {
SortedMap<Long, Integer> subMap = times.subMap(startInterval, Math.min(endInterval, endTime + 1));
longcount = 0;

for (longtime : subMap.keySet()) {
count += subMap.get(time);
 }

result[idx] = count;
 ++idx;

startInterval += delta;
endInterval += delta;
 }

returnresult;
 }

privatelonggetDelta(Frequencyf) {
if (Frequency.MINUTE == f) {
return60 * 1000;
 } elseif (Frequency.HOUR == f) {
return60 * 60 * 1000;
 } elseif (Frequency.DAY == f) {
return60 * 60 * 24 * 1000;
 } else {
return0L;
 }
 }

publicstaticvoidmain(String[] args) {
TT1tweetCounts = newTT1();

tweetCounts.recordTweet("tweet3", 0);
tweetCounts.recordTweet("tweet3", 60000);
tweetCounts.recordTweet("tweet3", 10000);
tweetCounts.recordTweet("tweet3", 10000);

System.out
 .println(Arrays.toString(tweetCounts.getTweetCountsPerFrequency(Frequency.MINUTE, "tweet3", 0, 59000)));
System.out
 .println(Arrays.toString(tweetCounts.getTweetCountsPerFrequency(Frequency.MINUTE, "tweet3", 0, 60000)));

tweetCounts.recordTweet("tweet3", 120000);

System.out
 .println(Arrays.toString(tweetCounts.getTweetCountsPerFrequency(Frequency.HOUR, "tweet3", 0, 210000)));

return;
 }
}