_1152.java

packagecom.fishercoder.solutions.secondthousand;

importjava.util.ArrayList;
importjava.util.HashMap;
importjava.util.HashSet;
importjava.util.List;
importjava.util.Map;
importjava.util.Set;
importjava.util.TreeMap;

publicclass_1152 {
publicstaticclassSolution1 {
publicList<String> mostVisitedPattern(
String[] username, int[] timestamp, String[] website) {
Map<String, TreeMap<Integer, String>> userToSiteMap = newHashMap<>();
for (inti = 0; i < username.length; i++) {
if (!userToSiteMap.containsKey(username[i])) {
userToSiteMap.put(username[i], newTreeMap<>());
 }
TreeMap<Integer, String> timeToSiteMap = userToSiteMap.get(username[i]);
timeToSiteMap.put(timestamp[i], website[i]);
userToSiteMap.put(username[i], timeToSiteMap);
 }
Map<String, Integer> sequenceCountMap = newHashMap<>();
for (Stringuser : userToSiteMap.keySet()) {
TreeMap<Integer, String> timeToSiteMap = userToSiteMap.get(user);
if (timeToSiteMap.size() < 3) {
continue;
 } else {
List<Integer> times = newArrayList<>();
for (inttime : timeToSiteMap.keySet()) {
times.add(time);
 }
List<String> allSequences = formAllSequences(times, timeToSiteMap);
Set<String> encounteredSequence = newHashSet<>();
for (Stringsequence : allSequences) {
if (encounteredSequence.add(sequence)) {
sequenceCountMap.put(
sequence, sequenceCountMap.getOrDefault(sequence, 0) + 1);
 }
 }
 }
 }
List<String> mostVisitedPattern = newArrayList<>();
intcount = 0;
Stringresult = null;
for (Stringsequence : sequenceCountMap.keySet()) {
if (sequenceCountMap.get(sequence) > count) {
result = sequence;
count = sequenceCountMap.get(sequence);
 } elseif (count == sequenceCountMap.get(sequence)) {
if (sequence.compareTo(result) < 0) {
result = sequence;
 }
 }
 }
for (Stringsite : result.split("->")) {
mostVisitedPattern.add(site);
 }
returnmostVisitedPattern;
 }

privateList<String> formAllSequences(
List<Integer> times, TreeMap<Integer, String> timeToSiteMap) {
List<String> result = newArrayList<>();
for (inti = 0; i < times.size() - 2; i++) {
for (intj = i + 1; j < times.size() - 1; j++) {
for (intk = j + 1; k < times.size(); k++) {
result.add(
timeToSiteMap.get(times.get(i))
 + "->"
 + timeToSiteMap.get(times.get(j))
 + "->"
 + timeToSiteMap.get(times.get(k)));
 }
 }
 }
returnresult;
 }
 }
}