Dynamic Array

Issue TheAlgorithms#96

Author: t0rr3sp3dr0

data_structures/Lists/DynamicArray.java

@@ -0,0 +1,73 @@
+import java.util.*;
+
+public class DynamicArray<E> {
+    private Object[] array;
+    private int size;
+
+    public DynamicArray(int initialCapacity) {
+        this.array = new Object[initialCapacity];
+        this.size = 0;
+    }
+
+    private void resize() {
+        Object[] array = this.array;
+        this.array = new Object[array.length * 2];
+        System.arraycopy(array, 0, this.array, 0, array.length);
+    }
+
+    public void add(E e) {
+        if (this.size == array.length)
+            this.resize();
+
+        this.array[this.size++] = e;
+    }
+
+    public void add(int index, E e) {
+        if (this.size == array.length)
+            this.resize();
+
+        System.arraycopy(this.array, index, this.array, index + 1, this.size - index);
+        this.array[index] = e;
+        this.size++;
+    }
+
+    public E get(int index) {
+        //noinspection unchecked
+        return (E) this.array[index];
+    }
+
+    public void set(int index, E e) {
+        if (this.array[index] == null && e != null)
+            ++this.size;
+        else if (e == null && this.array[index] != null)
+            --this.size;
+
+        this.array[index] = e;
+    }
+
+    public int size() {
+        return this.size;
+    }
+
+    public int capacity() {
+        return this.array.length;
+    }
+
+    public int indexOf(E e) {
+        for (int i = 0; i < this.size; i++)
+            if (this.array[i].equals(e))
+                return i;
+
+        return this.size;
+    }
+
+    public static void main(String[] args) {
+        DynamicArray<Integer> v = new DynamicArray<>(11);
+
+        for (int i = 0; i < 100; i++)
+            v.add(i);
+
+        for (int i = 0; i < 100; i++)
+            System.out.println(v.get(i));
+    }
+}