ArrayList/enduf7686

src/main/java/List/ArrayList/ArrayList_enduf7686.java

@@ -0,0 +1,74 @@
+package List.ArrayList;
+
+import static java.lang.System.arraycopy;
+
+import List.List;
+
+public class ArrayList_enduf7686<E> implements List<E> {
+
+    private static final int DEFAULT_INIT_SIZE = 10;
+
+    private Object[] array;
+    private int size;
+
+    public ArrayList_enduf7686() {
+        this(DEFAULT_INIT_SIZE);
+    }
+
+    public ArrayList_enduf7686(int initSize) {
+        this.array = new Object[initSize];
+        this.size = 0;
+    }
+
+    @Override
+    public void insert(E data) {
+        array[size++] = data;
+
+        if (array.length == size) {
+            Object[] temp = array.clone();
+
+            array = new Object[size + DEFAULT_INIT_SIZE];
+            arraycopy(temp, 0, array, 0, temp.length);
+        }
+    }
+
+    @Override
+    public int size() {
+        return size;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return size == 0;
+    }
+
+    @Override
+    public boolean contains(E o) {
+        for (int i = 0; i <= size; i++) {
+            if (o.equals(array[i])) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public E get(int index) {
+        return (E) array[index];
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public E remove(int index) {
+        E temp = (E) array[index];
+
+        for (int idx = index + 1; idx < array.length; idx++) {
+            array[idx - 1] = array[idx];
+        }
+        array[--size] = null;
+
+        return temp;
+    }
+}

src/test/java/List/ArrayList/ArrayListTest_enduf7686.java

@@ -0,0 +1,104 @@
+package List.ArrayList;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+import List.List;
+import org.junit.jupiter.api.Test;
+
+public class ArrayListTest_enduf7686 {
+
+    @Test
+    void ArrayList의_생성_및_초기화() {
+        // 구현 후 수정
+        List<Integer> list = new ArrayList_enduf7686<>();
+
+        assertThat(list).isNotNull();
+    }
+
+    @Test
+    void 데이터_5개_저장() {
+        // 구현 후 수정
+        List<Integer> list = new ArrayList_enduf7686<Integer>();
+
+        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() {
+        // 구현 후 수정
+        List<Integer> list = new ArrayList_enduf7686<Integer>();
+
+        list.insert(11);
+        list.insert(11);
+        list.insert(22);
+        list.insert(22);
+        list.insert(33);
+
+        // Iterable을 구현하면 enhanced for loop를 사용할 수 있습니다.
+        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_5개_저장_후_데이터_확인() {
+        // 구현 후 수정
+        List<Integer> list = new ArrayList_enduf7686<Integer>();
+
+        list.insert(11);
+        list.insert(11);
+        list.insert(22);
+        list.insert(22);
+        list.insert(33);
+
+        assertThat(list.contains(11)).isEqualTo(true);
+        assertThat(list.contains(12)).isEqualTo(false);
+        assertThat(list.contains(22)).isEqualTo(true);
+        assertThat(list.contains(33)).isEqualTo(true);
+        assertThat(list.contains(34)).isEqualTo(false);
+    }
+
+    @Test
+    void 데이터_15개_저장_후_데이터_확인() {
+        // 구현 후 수정
+        List<Integer> list = new ArrayList_enduf7686<Integer>();
+
+        list.insert(11);
+        list.insert(11);
+        list.insert(22);
+        list.insert(22);
+        list.insert(33);
+        list.insert(33);
+        list.insert(44);
+        list.insert(44);
+        list.insert(44);
+        list.insert(55);
+        list.insert(55);
+        list.insert(55);
+        list.insert(66);
+        list.insert(77);
+        list.insert(88);
+
+        assertThat(list.size()).isEqualTo(15);
+    }
+}