diff --git a/src/main/java/practice/CandidateValidator.java b/src/main/java/practice/CandidateValidator.java index 8d2e56c0e..4b06748a9 100644 --- a/src/main/java/practice/CandidateValidator.java +++ b/src/main/java/practice/CandidateValidator.java @@ -1,5 +1,24 @@ 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_AGE = 35; + private static final int REQUIRED_YEARS = 10; + private static final String NATIONALITY = "Ukrainian"; + + @Override + public boolean test(Candidate c) { + return c.getAge() >= MIN_AGE + && c.isAllowedToVote() + && NATIONALITY.equals(c.getNationality()) + && yearsInUkraine(c.getPeriodsInUkr()) >= REQUIRED_YEARS; + } + + private int yearsInUkraine(String periods) { + String[] years = periods.split("-"); + return Integer.parseInt(years[1]) - Integer.parseInt(years[0]); + } } diff --git a/src/main/java/practice/StreamPractice.java b/src/main/java/practice/StreamPractice.java index 57b1ca2e2..e73d8b763 100644 --- a/src/main/java/practice/StreamPractice.java +++ b/src/main/java/practice/StreamPractice.java @@ -1,80 +1,73 @@ package practice; -import java.util.Collections; +import java.util.Arrays; import java.util.List; +import java.util.NoSuchElementException; +import java.util.stream.Collectors; +import java.util.stream.IntStream; import model.Candidate; +import model.Cat; import model.Person; +import model.Person.Sex; 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' >" - */ + public int findMinEvenNumber(List numbers) { - return 0; + return numbers.stream() + .flatMap(a -> Arrays.stream(a.split(","))) + .map(String::trim) + .mapToInt(Integer::parseInt) + .filter(n -> n % 2 == 0) + .min() + .orElseThrow(() -> new RuntimeException( + "Can't get min value from list: " + numbers)); } - /** - * 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()) + .mapToObj(i -> i % 2 != 0 ? numbers.get(i) - 1 : numbers.get(i)) + .filter(n -> n % 2 != 0) + .mapToInt(Integer::intValue) + .average() + .orElseThrow(NoSuchElementException::new); } - /** - * 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(); + return peopleList.stream() + .filter(p -> Sex.MAN.equals(p.getSex()) + && p.getAge() >= fromAge + && p.getAge() <= toAge) + .collect(Collectors.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(); + int maleToAge, List peopleList) { + return peopleList.stream() + .filter(p -> (Sex.MAN.equals(p.getSex()) + && p.getAge() >= fromAge + && p.getAge() <= maleToAge) + || (Sex.WOMAN.equals(p.getSex()) + && p.getAge() >= fromAge + && p.getAge() <= femaleToAge)) + .collect(Collectors.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(p -> Sex.WOMAN.equals(p.getSex()) + && p.getAge() >= femaleAge + && p.getCats() != null + && !p.getCats().isEmpty()) + .flatMap(p -> p.getCats().stream()) + .map(Cat::getName) + .collect(Collectors.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(new CandidateValidator()) + .map(Candidate::getName) + .sorted() + .collect(Collectors.toList()); } }