package algorithm; public class ArrayList { private int size = 0; private Object[] elementData = new Object[100]; public boolean addFirst(Object element) { return add(0,element); } public boolean addLast(Object element) { elementData[size] = element; size++; return true; } public boolean add(int index,Object element) { for(int i = size-1;i>=index;i--) { elementData[i+1] = elementData[i]; } eleme..