The collections api - Data Structures and Problem Solving Using Java - page 288

public abstract class AbstractCollection<AnyType>
implements Collection<AnyType>
{
public boolean removeAll ( Collection<? extends AnyType> c )
{
Iterator<AnyType> itr = this.iterator( );
boolean wasChanged = false;

while( itr.hasNext( ) )
{
if( c.contains( itr.next( ) ) )
{
itr.remove( );
wasChanged = true;
}
}
return wasChanged;
}
...
}

a. Suppose LinkedList extends AbtractCollection and does not over-

ride removeAll . What is the running time of removeAll when c is a
List ?

b. Suppose LinkedList extends AbstractCollection and does not over-

ride removeAll . What is the running time of removeAll when c is a
TreeSet ?

c. Suppose ArrayList extends AbstractCollection and does not over-

ride removeAll . What is the running time of removeAll when c is a
List ?

d. Suppose ArrayList extends AbstractCollection and does not over-

ride removeAll . What is the running time of removeAll when c is a
TreeSet ?

e. What is the result of calling c.removeAll(c) using the implemen-

tation above?

f. Explain how to add code so that a call such as c.removeAll(c)

clears the collection.

Write a test program to see which of the following calls successfully
clears a java LinkedList .
c.removeAll( c );
c.removeAll( c.subList ( 0, c.size( ) );

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