A stupid dynamic array,

DynamicArray,java

public class Array<E> {
  public Unit[] arr;
  public int size;
  private int last_inserted = -1;
  private class Unit<E> {
    public E data;
    
    Unit(E thing) {
      this.data = thing;
    }
  }
  
  Array(int size) {
    this.size = size;
    this.arr = new Unit[this.size];
  }
  
  public void append(E thing) {
    if (last_inserted + 1 >= size) {
      Unit[] temp_arr = new Unit[this.size * 2];
      
      System.arraycopy(this.arr, 0, temp_arr, 0, this.size);
      this.arr = temp_arr;
      this.size *= 2;
    }
    last_inserted++;
    Unit u = new Unit(thing);
    this.arr[last_inserted] = u; 
  }
  
}