From d766c0b2298ad7809c43b2b2e8804dcf9e05fae4 Mon Sep 17 00:00:00 2001 From: Jack Tyler Date: Tue, 31 Mar 2026 12:01:23 +0300 Subject: [PATCH 1/2] Stream Practice solution --- .../java/practice/CandidateValidator.java | 17 +++++- src/main/java/practice/StreamPractice.java | 53 ++++++++++++++++--- 2 files changed, 61 insertions(+), 9 deletions(-) diff --git a/src/main/java/practice/CandidateValidator.java b/src/main/java/practice/CandidateValidator.java index 8d2e56c0e..3cdba9e45 100644 --- a/src/main/java/practice/CandidateValidator.java +++ b/src/main/java/practice/CandidateValidator.java @@ -1,5 +1,18 @@ package practice; -public class CandidateValidator { - //write your code here +import java.util.function.Predicate; +import model.Candidate; + +public class CandidateValidator implements Predicate { + + @Override + public boolean test(Candidate candidate) { + int from = Integer.parseInt(candidate.getPeriodsInUkr().split("-")[0]); + int to = Integer.parseInt(candidate.getPeriodsInUkr().split("-")[1]); + return candidate.getClass() == Candidate.class + && candidate.getAge() >= 35 + && candidate.isAllowedToVote() + && candidate.getNationality().equals("Ukrainian") + && to - from >= 10; + } } diff --git a/src/main/java/practice/StreamPractice.java b/src/main/java/practice/StreamPractice.java index 57b1ca2e2..c36784583 100644 --- a/src/main/java/practice/StreamPractice.java +++ b/src/main/java/practice/StreamPractice.java @@ -1,8 +1,11 @@ package practice; -import java.util.Collections; +import java.util.Arrays; +import java.util.Comparator; import java.util.List; +import java.util.NoSuchElementException; import model.Candidate; +import model.Cat; import model.Person; public class StreamPractice { @@ -14,7 +17,13 @@ public class StreamPractice { * "Can't get min value from list: < Here is our input 'numbers' >" */ public int findMinEvenNumber(List numbers) { - return 0; + return numbers.stream() + .flatMap(s -> Arrays.stream(s.split(","))) + .mapToInt(Integer::parseInt) + .filter(n -> n % 2 == 0) + .min() + .orElseThrow(() -> + new RuntimeException("Can't get min value from list: " + numbers)); } /** @@ -23,7 +32,16 @@ public int findMinEvenNumber(List numbers) { * But before that subtract 1 from each element on an odd position (having the odd index). */ public Double getOddNumsAverage(List numbers) { - return 0D; + for (int i = 1; i < numbers.size(); i = i + 2) { + numbers.set(i, numbers.get(i) - 1); + } + return numbers + .stream() + .filter(n -> n % 2 == 1) + .mapToInt(Integer::intValue) + .average() + .orElseThrow(NoSuchElementException::new); + } /** @@ -35,7 +53,10 @@ public Double getOddNumsAverage(List numbers) { * 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(person -> person.getSex().equals(Person.Sex.MAN)) + .filter(person -> person.getAge() >= fromAge && person.getAge() <= toAge) + .toList(); } /** @@ -50,7 +71,16 @@ public List selectMenByAge(List peopleList, int fromAge, int toA */ public List getWorkablePeople(int fromAge, int femaleToAge, int maleToAge, List peopleList) { - return Collections.emptyList(); + return peopleList.stream() + .filter(person -> + person.getSex().equals(Person.Sex.MAN) + && person.getAge() >= fromAge + && person.getAge() <= maleToAge + || person.getSex().equals(Person.Sex.WOMAN) + && person.getAge() >= fromAge + && person.getAge() <= femaleToAge + ) + .toList(); } /** @@ -59,7 +89,12 @@ public List getWorkablePeople(int fromAge, int femaleToAge, * 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().equals(Person.Sex.WOMAN)) + .filter(person -> ! person.getCats().isEmpty()) + .filter(person -> person.getAge() >= femaleAge) + .flatMap(person -> person.getCats().stream()) + .map(Cat::getName).toList(); } /** @@ -75,6 +110,10 @@ public List getCatsNames(List peopleList, int femaleAge) { * parametrized with Candidate in CandidateValidator. */ public List validateCandidates(List candidates) { - return Collections.emptyList(); + CandidateValidator validator = new CandidateValidator(); + return candidates.stream() + .filter(validator).sorted(Comparator.comparing(Candidate::getName)) + .map(Candidate::getName) + .toList(); } } From 48b437c8d9389aa25f134386d93ddf229591d40e Mon Sep 17 00:00:00 2001 From: Jack Tyler Date: Tue, 31 Mar 2026 12:18:37 +0300 Subject: [PATCH 2/2] fix on review --- src/main/java/practice/CandidateValidator.java | 9 ++++++--- src/main/java/practice/StreamPractice.java | 10 +++------- 2 files changed, 9 insertions(+), 10 deletions(-) diff --git a/src/main/java/practice/CandidateValidator.java b/src/main/java/practice/CandidateValidator.java index 3cdba9e45..962849e50 100644 --- a/src/main/java/practice/CandidateValidator.java +++ b/src/main/java/practice/CandidateValidator.java @@ -4,15 +4,18 @@ import model.Candidate; public class CandidateValidator implements Predicate { + private static final int ELIGIBLE_AGE = 35; + private static final int ELIGIBLE_TENURE = 10; + private static final String ELIGIBLE_NATIONALITY = "Ukrainian"; @Override public boolean test(Candidate candidate) { int from = Integer.parseInt(candidate.getPeriodsInUkr().split("-")[0]); int to = Integer.parseInt(candidate.getPeriodsInUkr().split("-")[1]); return candidate.getClass() == Candidate.class - && candidate.getAge() >= 35 + && candidate.getAge() >= ELIGIBLE_AGE && candidate.isAllowedToVote() - && candidate.getNationality().equals("Ukrainian") - && to - from >= 10; + && candidate.getNationality().equals(ELIGIBLE_NATIONALITY) + && to - from >= ELIGIBLE_TENURE; } } diff --git a/src/main/java/practice/StreamPractice.java b/src/main/java/practice/StreamPractice.java index c36784583..9b47ac11b 100644 --- a/src/main/java/practice/StreamPractice.java +++ b/src/main/java/practice/StreamPractice.java @@ -4,6 +4,7 @@ import java.util.Comparator; import java.util.List; import java.util.NoSuchElementException; +import java.util.stream.IntStream; import model.Candidate; import model.Cat; import model.Person; @@ -32,16 +33,11 @@ public int findMinEvenNumber(List numbers) { * But before that subtract 1 from each element on an odd position (having the odd index). */ public Double getOddNumsAverage(List numbers) { - for (int i = 1; i < numbers.size(); i = i + 2) { - numbers.set(i, numbers.get(i) - 1); - } - return numbers - .stream() + return IntStream.range(0, numbers.size()) + .map(i -> i % 2 != 0 ? numbers.get(i) - 1 : numbers.get(i)) .filter(n -> n % 2 == 1) - .mapToInt(Integer::intValue) .average() .orElseThrow(NoSuchElementException::new); - } /**