From 29fdda381432d41a174a54c5628a56b73b781a3e Mon Sep 17 00:00:00 2001 From: Yelyzaveta Korniienkova Date: Sun, 29 Mar 2026 10:23:54 +0200 Subject: [PATCH 1/3] stream practice --- .../java/practice/CandidateValidator.java | 24 ++++++++-- src/main/java/practice/StreamPractice.java | 48 ++++++++++++++++--- 2 files changed, 63 insertions(+), 9 deletions(-) diff --git a/src/main/java/practice/CandidateValidator.java b/src/main/java/practice/CandidateValidator.java index 8d2e56c0e..f65434a88 100644 --- a/src/main/java/practice/CandidateValidator.java +++ b/src/main/java/practice/CandidateValidator.java @@ -1,5 +1,23 @@ package practice; -public class CandidateValidator { - //write your code here -} +import model.Candidate; + +import java.util.function.Predicate; + +public class CandidateValidator implements Predicate { + + @Override + public boolean test(Candidate c) { + return c.getAge() > 35 + && c.isAllowedToVote() + && "Ukrainian".equals(c.getNationality()) + && getYearsInUkraine(c.getPeriodsInUkr()) >= 10; + } + + private int getYearsInUkraine(String period) { + String[] parts = period.split("-"); + int start = Integer.parseInt(parts[0]); + int end = Integer.parseInt(parts[1]); + return end - start; + } +} \ No newline at end of file diff --git a/src/main/java/practice/StreamPractice.java b/src/main/java/practice/StreamPractice.java index 57b1ca2e2..68c37503c 100644 --- a/src/main/java/practice/StreamPractice.java +++ b/src/main/java/practice/StreamPractice.java @@ -1,8 +1,14 @@ package practice; +import java.util.Arrays; import java.util.Collections; 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; public class StreamPractice { @@ -14,7 +20,14 @@ 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 +36,11 @@ 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) { - return 0D; + return IntStream.range(0, numbers.size()) + .map(i -> i % 2 != 0 ? numbers.get(i) - 1 : numbers.get(i)) + .filter(n -> n % 2 != 0) + .average() + .orElseThrow(NoSuchElementException::new); } /** @@ -35,7 +52,10 @@ 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(p -> p.getSex() == Person.Sex.MAN) + .filter(p -> p.getAge() >= fromAge && p.getAge() <= toAge) + .collect(Collectors.toList()); } /** @@ -50,7 +70,14 @@ 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(p -> { + int age = p.getAge(); + return p.getSex() == Person.Sex.MAN + ? age >= fromAge && age <= maleToAge + : age >= fromAge && age <= femaleToAge; + }) + .collect(Collectors.toList()); } /** @@ -59,7 +86,12 @@ 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(p -> p.getSex() == Person.Sex.WOMAN) + .filter(p -> p.getAge() >= femaleAge) + .flatMap(p -> p.getCats().stream()) + .map(Cat::getName) + .collect(Collectors.toList()); } /** @@ -75,6 +107,10 @@ public List getCatsNames(List peopleList, int femaleAge) { * parametrized with Candidate in CandidateValidator. */ public List validateCandidates(List candidates) { - return Collections.emptyList(); + return candidates.stream() + .filter(new CandidateValidator()) // используем наш Predicate + .map(Candidate::getName) // берём имя + .sorted() // сортируем по алфавиту + .collect(Collectors.toList()); } } From 94d2f1c1378ec9f35cd2f9039608fc96f6e86189 Mon Sep 17 00:00:00 2001 From: Yelyzaveta Korniienkova Date: Sun, 29 Mar 2026 11:06:40 +0200 Subject: [PATCH 2/3] stream practice --- src/main/java/practice/CandidateValidator.java | 11 ++++++----- src/main/java/practice/StreamPractice.java | 8 +++----- 2 files changed, 9 insertions(+), 10 deletions(-) diff --git a/src/main/java/practice/CandidateValidator.java b/src/main/java/practice/CandidateValidator.java index f65434a88..d5fdca621 100644 --- a/src/main/java/practice/CandidateValidator.java +++ b/src/main/java/practice/CandidateValidator.java @@ -1,17 +1,18 @@ package practice; -import model.Candidate; - import java.util.function.Predicate; +import model.Candidate; public class CandidateValidator implements Predicate { + public static final int MIN_AGE = 35; + public static final int MIN_PERIOD_IN_UKRAINE = 10; @Override public boolean test(Candidate c) { - return c.getAge() > 35 + return c.getAge() >= MIN_AGE && c.isAllowedToVote() && "Ukrainian".equals(c.getNationality()) - && getYearsInUkraine(c.getPeriodsInUkr()) >= 10; + && getYearsInUkraine(c.getPeriodsInUkr()) >= MIN_PERIOD_IN_UKRAINE; } private int getYearsInUkraine(String period) { @@ -20,4 +21,4 @@ private int getYearsInUkraine(String period) { int end = Integer.parseInt(parts[1]); return end - start; } -} \ No newline at end of file +} diff --git a/src/main/java/practice/StreamPractice.java b/src/main/java/practice/StreamPractice.java index 68c37503c..3c431df43 100644 --- a/src/main/java/practice/StreamPractice.java +++ b/src/main/java/practice/StreamPractice.java @@ -1,12 +1,10 @@ package practice; import java.util.Arrays; -import java.util.Collections; 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; @@ -108,9 +106,9 @@ public List getCatsNames(List peopleList, int femaleAge) { */ public List validateCandidates(List candidates) { return candidates.stream() - .filter(new CandidateValidator()) // используем наш Predicate - .map(Candidate::getName) // берём имя - .sorted() // сортируем по алфавиту + .filter(new CandidateValidator()) + .map(Candidate::getName) + .sorted() .collect(Collectors.toList()); } } From 9601989b6ec0600f362335cf84196fef072131b6 Mon Sep 17 00:00:00 2001 From: Yelyzaveta Korniienkova Date: Sun, 29 Mar 2026 11:18:05 +0200 Subject: [PATCH 3/3] stream practice --- src/main/java/practice/CandidateValidator.java | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/main/java/practice/CandidateValidator.java b/src/main/java/practice/CandidateValidator.java index d5fdca621..437460b5a 100644 --- a/src/main/java/practice/CandidateValidator.java +++ b/src/main/java/practice/CandidateValidator.java @@ -6,12 +6,13 @@ public class CandidateValidator implements Predicate { public static final int MIN_AGE = 35; public static final int MIN_PERIOD_IN_UKRAINE = 10; + public static final String NATIONALITY = "Ukrainian"; @Override public boolean test(Candidate c) { return c.getAge() >= MIN_AGE && c.isAllowedToVote() - && "Ukrainian".equals(c.getNationality()) + && NATIONALITY.equals(c.getNationality()) && getYearsInUkraine(c.getPeriodsInUkr()) >= MIN_PERIOD_IN_UKRAINE; }