| # | Title | Solutions | Video | Difficulty | Tag

|-----|----------------|---------------|--------|-------------|-------------

|1604|[Alert Using Same Key-Card Three or More Times in a One Hour Period](https://leetcode.com/problems/alert-using-same-key-card-three-or-more-times-in-a-one-hour-period/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1604.java)||Medium|String, Ordered Map|

|1603|[Design Parking System](https://leetcode.com/problems/design-parking-system/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1603.java)||Easy|Design|

|1601|[Maximum Number of Achievable Transfer Requests](https://leetcode.com/problems/maximum-number-of-achievable-transfer-requests/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1601.java)||Hard|Backtracking|

|1598|[Crawler Log Folder](https://leetcode.com/problems/crawler-log-folder/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1598.java)||Easy|Stack|

packagecom.fishercoder.solutions;

importjava.util.ArrayList;

importjava.util.Collections;

importjava.util.HashMap;

importjava.util.List;

importjava.util.Map;

publicclass_1604 {

publicstaticclassSolution1 {

publicList<String>alertNames(String[]keyName,String[]keyTime) {

Map<String,List<String>>map =newHashMap<>();

for (inti =0;i <keyName.length;i++) {

if (!map.containsKey(keyName[i])) {

map.put(keyName[i],newArrayList<>());

}

map.get(keyName[i]).add(keyTime[i]);

}

List<String>people =newArrayList<>();

for (Stringperson :map.keySet()) {

List<String>times =map.get(person);

List<Integer>minutes =newArrayList<>();

for (Stringtime :times) {

String[]hourAndMin =time.split(":");

Integerminute =Integer.parseInt(hourAndMin[0]) *60 +Integer.parseInt(hourAndMin[1]);

minutes.add(minute);

}

Collections.sort(minutes);

for (inti =0;i <minutes.size() -2;i++) {

if (minutes.get(i +2) -minutes.get(i) <=60) {

people.add(person);

break;

}

}

}

Collections.sort(people);

returnpeople;

}

}

}

packagecom.fishercoder;

importcom.fishercoder.solutions._1604;

importorg.junit.BeforeClass;

importorg.junit.Test;

importjava.util.Arrays;

importstaticjunit.framework.TestCase.assertEquals;

publicclass_1604Test {

privatestatic_1604.Solution1solution1;

publicstaticvoidsetup() {

solution1 =new_1604.Solution1();

}

publicvoidtest1() {

assertEquals(Arrays.asList("daniel"),solution1.alertNames(newString[]{"daniel","daniel","daniel","luis","luis","luis","luis"},newString[]{"10:00","10:40","11:00","09:00","11:00","13:00","15:00"}));

}

publicvoidtest2() {

assertEquals(Arrays.asList("bob"),solution1.alertNames(newString[]{"alice","alice","alice","bob","bob","bob","bob"},newString[]{"12:01","12:00","18:00","21:00","21:20","21:30","23:00"}));

}

publicvoidtest3() {

assertEquals(Arrays.asList(),solution1.alertNames(newString[]{"john","john","john"},newString[]{"23:58","23:59","00:01"}));

}

publicvoidtest4() {

assertEquals(Arrays.asList("clare","leslie"),solution1.alertNames(newString[]{"leslie","leslie","leslie","clare","clare","clare","clare"},newString[]{"13:00","13:20","14:00","18:00","18:51","19:30","19:49"}));

}

}