package com.nasuf.arraylist;
import java.util.Iterator;
import java.util.NoSuchElementException;
public class MyArrayList implements Iterable {
private static final int DEFAULT_CAPICITY = 10;
private int theSize;
private AnyType[] theItems;
public MyArrayList() {
clear();
}
public void clear() {
theSize = 0;
ensureCapacity(DEFAULT_CAPICITY);
}
public int size() {
return theSize;
}
public boolean isEmpty() {
return size() == 0;
}
public void trimToSize() {
ensureCapacity(size());
}
public AnyType get(int idx) {
if (idx < 0 || idx >= size())
throw new ArrayIndexOutOfBoundsException();
return theItems[idx];
}
public AnyType set(int idx, AnyType newVal) {
if (idx < 0 || idx >= size())
throw new ArrayIndexOutOfBoundsException();
AnyType old = theItems[idx];
theItems[idx] = newVal;
return old;
}
public void ensureCapacity(int newCapacity) {
if (newCapacity < theSize)
return;
AnyType [] old = theItems;
theItems = (AnyType []) new Object[ newCapacity ];
for (int i=0; iidx; i--)
theItems[i] = theItems[i=1];
theItems[idx] = x;
theSize ++;
}
public AnyType remove(int idx) {
AnyType removedItem = theItems[idx];
for(int i=idx; i iterator() {
return new ArrayListIterator();
}
private class ArrayListIterator implements Iterator {
private int current = 0;
@Override
public boolean hasNext() {
return current < size();
}
@Override
public AnyType next() {
if (!hasNext())
throw new NoSuchElementException();
return theItems[current++];
}
public void remove() {
MyArrayList.this.remove(--current);
}
}
}
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