Home work2

pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.example</groupId>
+    <artifactId>SberJavaHomeWork2</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+
+</project>

src/main/java/ru/sber/mironov/Car.java

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+package ru.sber.mironov;
+
+public class Car {
+    private final long carId;
+    private final String brand;
+    private final String modelName;
+    private final int maxVelocity;
+    private final int power;
+    private final int ownerId;
+
+    public Car(long carId, String brand, String modelName, int maxVelocity, int power, int ownerId) {
+        this.carId = carId;
+        this.brand = brand;
+        this.modelName = modelName;
+        this.maxVelocity = maxVelocity;
+        this.power = power;
+        this.ownerId = ownerId;
+    }
+
+
+    public String getBrand() {
+        return brand;
+    }
+
+    public String getModelName() {
+        return modelName;
+    }
+
+    public int getMaxVelocity() {
+        return maxVelocity;
+    }
+
+    public int getOwnerId() {
+        return ownerId;
+    }
+
+    public long getCarId() {
+        return carId;
+    }
+
+    public int getPower() {
+        return power;
+    }
+}

src/main/java/ru/sber/mironov/Garage.java

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+package ru.sber.mironov;
+
+import java.util.*;
+
+import static java.util.stream.Collectors.toList;
+
+public interface Garage {
+    HashMap<Owner, ArrayList<Car>> mapOwnerToCars = new HashMap<>();
+    HashMap<Car, Owner> mapCarToOwner = new HashMap<>();
+    HashMap<String, ArrayList<Car>> mapBrandToCar = new HashMap<>();
+    HashMap<Long, Car> cars = new HashMap<>();
+    HashMap<Long, Owner> owners = new HashMap<>();
+
+    default Collection<Owner> allCarsUniqueOwners() {
+        return mapOwnerToCars.keySet().stream()
+                .filter(o -> mapOwnerToCars.get(o).size() == 1)
+                .distinct()
+                .collect(toList());
+    }
+
+    /**
+     * Complexity should be less than O(n)
+     */
+    default Collection<Car> topThreeCarsByMaxVelocity() {
+        ArrayList<Car> sorted = new ArrayList<>();
+        for (Car car : cars.values()) {
+            sorted.add(car);
+            sorted.sort(Comparator.comparingInt(Car::getMaxVelocity));
+            if (sorted.size() > 3) {
+                sorted.remove(0);
+            }
+        }
+        return sorted;
+    }
+
+    /**
+     * Complexity should be O(1)
+     */
+    default Collection<Car> allCarsOfBrand(String brand) {
+        return mapBrandToCar.get(brand);
+    }
+
+    /**
+     * Complexity should be less than O(n)
+     */
+    default Collection<Car> carsWithPowerMoreThan(int power) {
+        return mapOwnerToCars.values().stream()
+                .flatMap(Collection::stream)
+                .filter(car -> car.getPower() >= power)
+                .distinct()
+                .collect(toList());
+
+    }
+
+    /**
+     * Complexity should be O(1)
+     */
+    default Collection<Car> allCarsOfOwner(Owner owner) {
+        return mapOwnerToCars.get(owner);
+    }
+
+    /**
+     * @return mean value of owner age that has cars with given brand
+     */
+    default int meanOwnersAgeOfCarBrand(String brand) {
+        return (int) mapBrandToCar.get(brand).stream()
+                .map(mapCarToOwner::get)
+                .mapToInt(Owner::getAge)
+                .average().getAsDouble();
+    }
+
+    /**
+     * @return mean value of cars for all owners
+     */
+    default int meanCarNumberForEachOwner() {
+        return (int) mapOwnerToCars.keySet().stream()
+                .mapToInt(owner -> mapOwnerToCars.get(owner).size())
+                .average().getAsDouble();
+    }
+
+    /**
+     * Complexity should be less than O(n)
+     *
+     * @return removed car
+     */
+    default Car removeCar(int carId) {
+        Car deleteCar = cars.get((long) carId);
+        Owner deleteOwner = owners.get((long) deleteCar.getOwnerId());
+
+        mapOwnerToCars.get(deleteOwner).remove(deleteCar);
+        if (mapOwnerToCars.get(deleteOwner).isEmpty()) {
+            mapOwnerToCars.remove(deleteOwner);
+            owners.remove(deleteOwner.getOwnerId());
+        }
+
+        mapBrandToCar.get(deleteCar.getBrand()).remove(deleteCar);
+        if (mapBrandToCar.get(deleteCar.getBrand()).isEmpty()) {
+            mapBrandToCar.remove(deleteCar.getBrand());
+        }
+
+        mapCarToOwner.remove(deleteCar);
+
+
+        cars.remove((long)carId);
+        return deleteCar;
+    }
+
+    /**
+     * Complexity should be less than O(n)
+     */
+    default void addCar(Car car, Owner owner) {
+
+        put(mapOwnerToCars, owner, car);
+        put(mapBrandToCar, car.getBrand(), car);
+
+        mapCarToOwner.put(car, owner);
+        cars.put(car.getCarId(), car);
+        owners.put(owner.getOwnerId(), owner);
+    }
+
+    private <K, V> void put(HashMap<K, ArrayList<V>> collectionHashMap, K key, V value) {
+        if (collectionHashMap.containsKey(key)) {
+            collectionHashMap.get(key).add(value);
+        } else {
+            collectionHashMap.put(key, new ArrayList<>(Collections.singletonList(value)));
+        }
+    }
+}

src/main/java/ru/sber/mironov/Main.java

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+package ru.sber.mironov;
+
+public class Main {
+    public static void main(String[] args) {
+
+    }
+}

src/main/java/ru/sber/mironov/MyGarage.java

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+package ru.sber.mironov;
+
+public class MyGarage implements Garage{
+}

src/main/java/ru/sber/mironov/Owner.java

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+package ru.sber.mironov;
+
+public class Owner {
+    private final long ownerId;
+    private final String name;
+    private final String lastName;
+    private final int age;
+
+    public Owner(long ownerId, String name, String lastName, int age) {
+        this.ownerId = ownerId;
+        this.name = name;
+        this.lastName = lastName;
+        this.age = age;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public long getOwnerId() {
+        return ownerId;
+    }
+
+    public int getAge() {
+        return age;
+    }
+}