diff --git a/src/main/java/practice/CandidateValidator.java b/src/main/java/practice/CandidateValidator.java index 8d2e56c0e..b8c7a8301 100644 --- a/src/main/java/practice/CandidateValidator.java +++ b/src/main/java/practice/CandidateValidator.java @@ -1,5 +1,28 @@ package practice; -public class CandidateValidator { - //write your code here +import java.util.function.Predicate; +import model.Candidate; + +public class CandidateValidator implements Predicate { + private static final int MIN_PERIOD_LIVE_IN_COUNTRY = 10; + private static final int MIN_VALID_AGE = 35; + private static final int FROM_YEAR_INDEX = 0; + private static final int UP_TO_YEAR_INDEX = 1; + private static final String VALID_NATIONALITY = "Ukrainian"; + private static final String DIVIDER_DASH = "-"; + + @Override + public boolean test(Candidate candidate) { + return candidate.isAllowedToVote() + && candidate.getAge() >= MIN_VALID_AGE + && VALID_NATIONALITY.equals(candidate.getNationality()) + && yearsLiveInUkraine(candidate) >= MIN_PERIOD_LIVE_IN_COUNTRY; + } + + private int yearsLiveInUkraine(Candidate candidate) { + String liveInUkraine = candidate.getPeriodsInUkr(); + int fromYear = Integer.parseInt(liveInUkraine.split(DIVIDER_DASH)[FROM_YEAR_INDEX]); + int upToYear = Integer.parseInt(liveInUkraine.split(DIVIDER_DASH)[UP_TO_YEAR_INDEX]); + return upToYear - fromYear; + } } diff --git a/src/main/java/practice/StreamPractice.java b/src/main/java/practice/StreamPractice.java index 57b1ca2e2..6de64c68b 100644 --- a/src/main/java/practice/StreamPractice.java +++ b/src/main/java/practice/StreamPractice.java @@ -1,80 +1,79 @@ package practice; -import java.util.Collections; +import java.util.Arrays; +import java.util.Collection; import java.util.List; +import java.util.function.Predicate; +import java.util.function.Supplier; +import java.util.stream.IntStream; import model.Candidate; +import model.Cat; import model.Person; public class StreamPractice { - /** - * Given list of strings where each element contains 1+ numbers: - * input = {"5,30,100", "0,22,7", ...} - * return min integer value. One more thing - we're interested in even numbers. - * If there is no needed data throw RuntimeException with message - * "Can't get min value from list: < Here is our input 'numbers' >" - */ + private static final String NUMBERS_DIVIDER = "[,]"; + private final CandidateValidator candidateValidator = new CandidateValidator(); + public int findMinEvenNumber(List numbers) { - return 0; + Supplier exceptionSupplier = () -> + new RuntimeException("Can't get min value from list: " + numbers); + return numbers.stream() + .map(string -> string.split(NUMBERS_DIVIDER)) + .flatMap(Arrays::stream) + .mapToInt(Integer::parseInt) + .filter(this::isEven) + .min() + .orElseThrow(exceptionSupplier); } - /** - * Given a List of Integer numbers, - * return the average of all odd numbers from the list or throw NoSuchElementException. - * But before that subtract 1 from each element on an odd position (having the odd index). - */ public Double getOddNumsAverage(List numbers) { - return 0D; + return IntStream.range(0, numbers.size()) + .map(number -> (!isEven(number)) ? numbers.get(number) - 1 : numbers.get(number)) + .filter(number -> number % 2 == 1) + .average() + .orElseThrow(); } - /** - * Given a List of `Person` instances (having `name`, `age` and `sex` fields), - * for example, `Arrays.asList( new Person(«Victor», 16, Sex.MAN), - * new Person(«Helen», 42, Sex.WOMAN))`, - * select from the List only men whose age is from `fromAge` to `toAge` inclusively. - *

- * Example: select men who can be recruited to army (from 18 to 27 years old inclusively). - */ public List selectMenByAge(List peopleList, int fromAge, int toAge) { - return Collections.emptyList(); + Predicate predicate = person -> + person.getSex() == Person.Sex.MAN + && person.getAge() >= fromAge + && person.getAge() <= toAge; + return peopleList.stream() + .filter(predicate) + .toList(); } - /** - * Given a List of `Person` instances (having `name`, `age` and `sex` fields), - * for example, `Arrays.asList( new Person(«Victor», 16, Sex.MAN), - * new Person(«Helen», 42, Sex.WOMAN))`, - * select from the List only people whose age is from `fromAge` and to `maleToAge` (for men) - * or to `femaleToAge` (for women) inclusively. - *

- * Example: select people of working age - * (from 18 y.o. and to 60 y.o. for men and to 55 y.o. for women inclusively). - */ public List getWorkablePeople(int fromAge, int femaleToAge, int maleToAge, List peopleList) { - return Collections.emptyList(); + Predicate predicate = person -> + (person.getSex() == Person.Sex.MAN && person.getAge() <= maleToAge) + || (person.getSex() == Person.Sex.WOMAN && person.getAge() <= femaleToAge); + return peopleList.stream() + .filter(person -> person.getAge() >= fromAge) + .filter(predicate) + .toList(); } - /** - * Given a List of `Person` instances (having `name`, `age`, `sex` and `cats` fields, - * and each `Cat` having a `name` and `age`), - * return the names of all cats whose owners are women from `femaleAge` years old inclusively. - */ public List getCatsNames(List peopleList, int femaleAge) { - return Collections.emptyList(); + return peopleList.stream() + .filter(person -> person.getSex() == Person.Sex.WOMAN + && person.getAge() >= femaleAge) + .map(Person::getCats) + .flatMap(Collection::stream) + .map(Cat::getName) + .toList(); } - /** - * Your help with a election is needed. Given list of candidates, where each element - * has Candidate.class type. - * Check which candidates are eligible to apply for president position and return their - * names sorted alphabetically. - * The requirements are: person should be older than 35 years, should be allowed to vote, - * have nationality - 'Ukrainian' - * and live in Ukraine for 10 years. For the last requirement use field periodsInUkr, - * which has following view: "2002-2015" - * We want to reuse our validation in future, so let's write our own impl of Predicate - * parametrized with Candidate in CandidateValidator. - */ public List validateCandidates(List candidates) { - return Collections.emptyList(); + return candidates.stream() + .filter(candidateValidator) + .map(Candidate::getName) + .sorted() + .toList(); + } + + private boolean isEven(int number) { + return number % 2 == 0; } }