[김민지] 자동차경주 1~2단계 제출합니다

src/main/java/Car.java

@@ -0,0 +1,27 @@
+public class Car {
+
+  private final String carName;
+  private int position = 0;
+  private final RandomMovable randomMovable;
+
+  public Car(String name, RandomMovable randomMovable, int position) {
+    this.carName = name;
+    this.randomMovable = randomMovable;
+    this.position = position;
+  }
+
+  public void move() {
+    if (randomMovable.canMove()) {
+      position++;
+    }
+  }
+
+  public String getCarName() {
+    return carName;
+  }
+
+  public int getPosition() {
+    return position;
+  }
+
+}

src/main/java/Movable.java

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+//움직일 수 있나? 만 보는 인터페이스
+@FunctionalInterface
+public interface Movable {
+  boolean canMove();
+}
+

src/main/java/RandomMovable.java

@@ -0,0 +1,18 @@
+import java.util.concurrent.ThreadLocalRandom;
+
+public class RandomMovable implements Movable {
+
+  private final int moveThreshold;
+  private final int randomBound;
+
+  //생성자에서 전진 조건을 설정
+  public RandomMovable(int moveThreshold, int randomBound) {
+    this.moveThreshold = moveThreshold;
+    this.randomBound = randomBound;
+  }
+
+  @Override
+  public boolean canMove() {
+    return (ThreadLocalRandom.current().nextInt(randomBound)) >= moveThreshold;
+  }
+}

src/main/java/Winners.java

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+import java.util.List;
+import java.util.stream.Collectors;
+
+public class Winners {
+
+  public static List<String> findWinnersNames(List<Car> cars) {
+
+    int maxPosition = cars.stream()
+        .mapToInt(Car::getPosition)
+        .max()
+        .orElse(0);//값이 비어있을 때는 우승 위치로 0을 사용
+
+    return cars.stream()
+        .filter(car -> car.getPosition() == maxPosition)
+        .map(Car::getCarName)
+        .collect(Collectors.toList());
+  }
+}

src/test/java/WinnersTest.java

@@ -0,0 +1,20 @@
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.List;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+public class WinnersTest {
+
+  @Test
+  @DisplayName("우승자(들) 이름을 반환한다")
+  void returnWinnerNames() {
+    Car normalCar = new Car("Car A", new RandomMovable(4, 10), 7);
+    Car electricCar = new Car("Car B", new RandomMovable(5, 10), 7);
+    Car truck = new Car("Car C", new RandomMovable(6, 10), 2);
+    Car mini = new Car("Car D", new RandomMovable(3, 10), 7);
+
+    List<Car> cars = List.of(normalCar, electricCar, truck, mini);
+    assertThat(Winners.findWinnersNames(cars)).containsExactlyInAnyOrder("Car A", "Car B", "Car D");
+  }
+}