LinkedList/hellomatia

src/main/java/List/LinkedList/LinkedList_hellomatia.java

@@ -0,0 +1,102 @@
+package List.LinkedList;
+
+import List.List;
+
+public class LinkedList_hellomatia<E> implements List<E> {
+    private final Node head;
+    private Node tail;
+    private int size;
+
+    public LinkedList_hellomatia() {
+        this.head = new Node(null);
+        this.tail = head;
+    }
+
+    @Override
+    public void insert(E data) {
+        tail.setNext(createNode(data));
+        tail = tail.getNext();
+        size++;
+    }
+
+    private Node createNode(E data) {
+        return new Node(data);
+    }
+
+    @Override
+    public int size() {
+        return size;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return size() == 0;
+    }
+
+    @Override
+    public boolean contains(E o) {
+        for (Node now = head.getNext(); now != null; now = now.getNext()) {
+            if (now.getData().equals(o)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public E get(int index) {
+        checkIndex(index);
+        return getNode(index).getData();
+    }
+
+    @Override
+    public E remove(int index) {
+        checkIndex(index);
+        Node removeNode = getNode(index);
+        Node prevNode = getNode(index - 1);
+        if (removeNode == tail) {
+            prevNode.setNext(null);
+            tail = prevNode;
+        } else {
+            prevNode.setNext(removeNode.getNext());
+        }
+        removeNode.setNext(null);
+        size--;
+        return removeNode.getData();
+    }
+
+    private void checkIndex(int index) {
+        if (index < 0 || index >= size()) {
+            throw new IndexOutOfBoundsException();
+        }
+    }
+
+    private Node getNode(int index) {
+        Node now = head.getNext();
+        for (int i = 0; i < index; i++) {
+            now = now.getNext();
+        }
+        return now;
+    }
+
+    private class Node {
+        private final E data;
+        private Node next;
+
+        protected Node(E data) {
+            this.data = data;
+        }
+
+        private Node getNext() {
+            return next;
+        }
+
+        private void setNext(Node next) {
+            this.next = next;
+        }
+
+        private E getData() {
+            return data;
+        }
+    }
+}

src/test/java/List/LinkedList/LinkedListTest.java

@@ -0,0 +1,167 @@
+package List.LinkedList;
+
+import static id.ID.hellomatia;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+import List.List;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class LinkedListTest {
+
+    private final LinkedListFactory<Integer> factory = new LinkedListFactory<>();
+    private List<Integer> list;
+
+    @BeforeEach
+    void init() {
+        list = factory.createList(hellomatia);
+    }
+
+    @Test
+    void LinkedList의_생성_및_초기화() {
+        assertThat(list).isNotNull();
+    }
+
+    @Test
+    void 데이터_5개_저장() {
+        list.insert(11);
+        list.insert(11);
+        list.insert(22);
+        list.insert(22);
+        list.insert(33);
+
+        assertThat(list.size()).isEqualTo(5);
+        assertThat(list.get(0)).isEqualTo(11);
+        assertThat(list.get(1)).isEqualTo(11);
+        assertThat(list.get(2)).isEqualTo(22);
+        assertThat(list.get(3)).isEqualTo(22);
+        assertThat(list.get(4)).isEqualTo(33);
+    }
+
+    @Test
+    void 데이터_5개_저장_후_22인_데이터_모두_삭제() {
+        list.insert(11);
+        list.insert(11);
+        list.insert(22);
+        list.insert(22);
+        list.insert(33);
+
+        for (int i = 0; i < list.size(); i++) {
+            if (list.get(i) == 22) {
+                list.remove(i);
+                i--; // 삭제되면 index가 조정되므로 해당 index부터 다시 확인해야 합니다.
+            }
+        }
+
+        assertThat(list.size()).isEqualTo(3);
+        assertThat(list.get(0)).isEqualTo(11);
+        assertThat(list.get(1)).isEqualTo(11);
+        assertThat(list.get(2)).isEqualTo(33);
+    }
+
+    @Test
+    void 데이터_중복_저장_후_모두_포함여부_확인() {
+        list.insert(11);
+        list.insert(11);
+        list.insert(22);
+        list.insert(22);
+        list.insert(33);
+
+        assertThat(list.contains(11)).isTrue();
+        assertThat(list.contains(22)).isTrue();
+        assertThat(list.contains(33)).isTrue();
+    }
+
+    @Test
+    void 비어있는_리스트_확인() {
+        assertThat(list.isEmpty()).isTrue();
+        list.insert(10);
+        assertThat(list.isEmpty()).isFalse();
+    }
+
+    @Test
+    void 데이터_삽입_후_크기_확인() {
+        assertThat(list.size()).isEqualTo(0);
+        list.insert(10);
+        assertThat(list.size()).isEqualTo(1);
+    }
+
+    @Test
+    void 유효하지_않은_인덱스로_데이터_가져오기() {
+        assertThatThrownBy(() -> list.get(0)).isInstanceOf(IndexOutOfBoundsException.class);
+        list.insert(10);
+        assertThatThrownBy(() -> list.get(-1)).isInstanceOf(IndexOutOfBoundsException.class);
+        assertThatThrownBy(() -> list.get(2)).isInstanceOf(IndexOutOfBoundsException.class);
+    }
+
+    @Test
+    void 유효하지_않은_인덱스로_데이터_삭제() {
+        assertThatThrownBy(() -> list.remove(0)).isInstanceOf(IndexOutOfBoundsException.class);
+        list.insert(10);
+        assertThatThrownBy(() -> list.remove(-1)).isInstanceOf(IndexOutOfBoundsException.class);
+        assertThatThrownBy(() -> list.remove(2)).isInstanceOf(IndexOutOfBoundsException.class);
+    }
+
+    @Test
+    void 모든_데이터_삭제_후_리스트_비우기() {
+        list.insert(10);
+        list.insert(20);
+        list.insert(30);
+
+        list.remove(0);
+        list.remove(0);
+        list.remove(0);
+
+        assertThat(list.size()).isEqualTo(0);
+        assertThat(list.isEmpty()).isTrue();
+    }
+
+    @Test
+    void 데이터_삽입_및_삭제_반복() {
+        list.insert(10);
+        list.insert(20);
+        list.insert(30);
+        list.insert(40);
+
+        list.remove(1);
+        list.insert(50);
+
+        assertThat(list.size()).isEqualTo(4);
+        assertThat(list.get(0)).isEqualTo(10);
+        assertThat(list.get(1)).isEqualTo(30);
+        assertThat(list.get(2)).isEqualTo(40);
+        assertThat(list.get(3)).isEqualTo(50);
+    }
+
+    @Test
+    void 리스트의_중간에_데이터_삽입() {
+        list.insert(10);
+        list.insert(20);
+        list.insert(30);
+
+        list.remove(1);
+        list.insert(25);
+
+        assertThat(list.size()).isEqualTo(3);
+        assertThat(list.get(0)).isEqualTo(10);
+        assertThat(list.get(1)).isEqualTo(30);
+        assertThat(list.get(2)).isEqualTo(25);
+    }
+
+    @Test
+    void 데이터_5개_삽입_후_모두_삭제() {
+        list.insert(10);
+        list.insert(20);
+        list.insert(30);
+        list.insert(40);
+        list.insert(50);
+
+        for (int i = 0; i < 5; i++) {
+            list.remove(0);
+        }
+
+        assertThat(list.size()).isEqualTo(0);
+        assertThat(list.isEmpty()).isTrue();
+    }
+}