solution for jv-stream-github-practise

src/main/java/practice/CandidateValidator.java

@@ -1,5 +1,26 @@
 package practice;
 
-public class CandidateValidator {
-    //write your code here
+import java.util.function.Predicate;
+import model.Candidate;
+/*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 class CandidateValidator implements Predicate<Candidate> {
+    public static final int MIN_AGE = 35;
+    public static final String NATIONALITY = "Ukrainian";
+    public static final int MIN_PERIOD = 10;
+
+    @Override
+    public boolean test(Candidate candidate) {
+        String[] period = candidate.getPeriodsInUkr().split("-");
+        int periodInt = Integer.parseInt(period[1]) - Integer.parseInt(period[0]);
+        return candidate.getAge() >= MIN_AGE
+                && candidate.getNationality().equals(NATIONALITY)
+                && periodInt >= MIN_PERIOD && candidate.isAllowedToVote();
+    }
 }

src/main/java/practice/StreamPractice.java

@@ -1,8 +1,12 @@
 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;
 
 public class StreamPractice {
@@ -14,7 +18,15 @@ public class StreamPractice {
      * "Can't get min value from list: < Here is our input 'numbers' >"
      */
     public int findMinEvenNumber(List<String> numbers) {
-        return 0;
+        if (numbers.isEmpty()) {
+            throw new RuntimeException("Can't get min value from list" + numbers);
+        }
+        return numbers.stream()
+                .flatMap(s -> Arrays.stream(s.split(",")))
+                .mapToInt(Integer::parseInt)
+                .filter(i -> i % 2 == 0)
+                .min()
+                .orElseThrow();
     }
 
     /**
@@ -23,7 +35,24 @@ public int findMinEvenNumber(List<String> numbers) {
      * But before that subtract 1 from each element on an odd position (having the odd index).
      */
     public Double getOddNumsAverage(List<Integer> numbers) {
-        return 0D;
+        IntStream.range(0, numbers.size())
+                .filter(x -> x % 2 == 1)
+                .forEach(i -> numbers.set(i, numbers.get(i) - 1));
+        long count = numbers.stream()
+                .filter(i -> i % 2 != 0)
+                .count();
+
+        if (count == 0) {
+            throw new NoSuchElementException();
+        }
+
+        long sum = numbers.stream()
+                .mapToInt(i -> i)
+                .filter(i -> i % 2 != 0)
+                .sum();
+
+        return (double) sum / count;
+
     }
 
     /**
@@ -35,7 +64,11 @@ public Double getOddNumsAverage(List<Integer> numbers) {
      * Example: select men who can be recruited to army (from 18 to 27 years old inclusively).
      */
     public List<Person> selectMenByAge(List<Person> peopleList, int fromAge, int toAge) {
-        return Collections.emptyList();
+        return peopleList.stream()
+                .filter(s -> s.getSex().equals(Person.Sex.MAN))
+                .filter(s -> s.getAge() >= fromAge)
+                .filter(s -> s.getAge() <= toAge)
+                .collect(Collectors.toList());
     }
 
     /**
@@ -50,7 +83,14 @@ public List<Person> selectMenByAge(List<Person> peopleList, int fromAge, int toA
      */
     public List<Person> getWorkablePeople(int fromAge, int femaleToAge,
                                           int maleToAge, List<Person> peopleList) {
-        return Collections.emptyList();
+        return peopleList.stream()
+                .filter(s -> (s.getSex().equals(Person.Sex.MAN)
+                        && s.getAge() <= maleToAge
+                        && s.getAge() >= fromAge)
+                        || (s.getSex().equals(Person.Sex.WOMAN)
+                        && s.getAge() <= femaleToAge
+                        && s.getAge() >= fromAge))
+                .collect(Collectors.toList());
     }
 
     /**
@@ -59,7 +99,13 @@ public List<Person> getWorkablePeople(int fromAge, int femaleToAge,
      * return the names of all cats whose owners are women from `femaleAge` years old inclusively.
      */
     public List<String> getCatsNames(List<Person> peopleList, int femaleAge) {
-        return Collections.emptyList();
+        return peopleList.stream()
+                .filter(s -> s.getSex().equals(Person.Sex.WOMAN)
+                        && s.getAge() >= femaleAge
+                        && !s.getCats().isEmpty())
+                .flatMap(person -> person.getCats().stream())
+                .map(Cat::getName)
+                .collect(Collectors.toList());
     }
 
     /**
@@ -75,6 +121,10 @@ public List<String> getCatsNames(List<Person> peopleList, int femaleAge) {
      * parametrized with Candidate in CandidateValidator.
      */
     public List<String> validateCandidates(List<Candidate> candidates) {
-        return Collections.emptyList();
+        return candidates.stream()
+                .filter(new CandidateValidator())
+                .map(Candidate::getName)
+                .sorted()
+                .collect(Collectors.toList());
     }
 }