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import java.util.EmptyStackException;
/*
* $Id: IntVector.java 468655 2006-10-28 07:12:06Z minchau $
*/
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: IntStack.java 468655 2006-10-28 07:12:06Z minchau $
*/
/**
* Implement a stack of simple integers.
*
* %OPT%
* This is currently based on IntVector, which permits fast acess but pays a
* heavy recopying penalty if/when its size is increased. If we expect deep
* stacks, we should consider a version based on ChunkedIntVector.
* @xsl.usage internal
*/
public class IntStack extends IntVector
{
/**
* Default constructor. Note that the default
* block size is very small, for small lists.
*/
public IntStack()
{
super();
}
/**
* Construct a IntVector, using the given block size.
*
* @param blocksize Size of block to allocate
*/
public IntStack(int blocksize)
{
super(blocksize);
}
/**
* Copy constructor for IntStack
*
* @param v IntStack to copy
*/
public IntStack (IntStack v)
{
super(v);
}
/**
* Pushes an item onto the top of this stack.
*
* @param i the int to be pushed onto this stack.
* @return the <code>item</code> argument.
*/
public int push(int i)
{
if ((m_firstFree + 1) >= m_mapSize)
{
m_mapSize += m_blocksize;
int newMap[] = new int[m_mapSize];
System.arraycopy(m_map, 0, newMap, 0, m_firstFree + 1);
m_map = newMap;
}
m_map[m_firstFree] = i;
m_firstFree++;
return i;
}
/**
* Removes the object at the top of this stack and returns that
* object as the value of this function.
*
* @return The object at the top of this stack.
*/
public final int pop()
{
return m_map[--m_firstFree];
}
/**
* Quickly pops a number of items from the stack.
*/
public final void quickPop(int n)
{
m_firstFree -= n;
}
/**
* Looks at the object at the top of this stack without removing it
* from the stack.
*
* @return the object at the top of this stack.
* @throws EmptyStackException if this stack is empty.
*/
public final int peek()
{
try {
return m_map[m_firstFree - 1];
}
catch (ArrayIndexOutOfBoundsException e)
{
throw new EmptyStackException();
}
}
/**
* Looks at the object at the position the stack counting down n items.
*
* @param n The number of items down, indexed from zero.
* @return the object at n items down.
* @throws EmptyStackException if this stack is empty.
*/
public int peek(int n)
{
try {
return m_map[m_firstFree-(1+n)];
}
catch (ArrayIndexOutOfBoundsException e)
{
throw new EmptyStackException();
}
}
/**
* Sets an object at a the top of the statck
*
*
* @param val object to set at the top
* @throws EmptyStackException if this stack is empty.
*/
public void setTop(int val)
{
try {
m_map[m_firstFree - 1] = val;
}
catch (ArrayIndexOutOfBoundsException e)
{
throw new EmptyStackException();
}
}
/**
* Tests if this stack is empty.
*
* @return <code>true</code> if this stack is empty;
* <code>false</code> otherwise.
* @since JDK1.0
*/
public boolean empty()
{
return m_firstFree == 0;
}
/**
* Returns where an object is on this stack.
*
* @param o the desired object.
* @return the distance from the top of the stack where the object is]
* located; the return value <code>-1</code> indicates that the
* object is not on the stack.
* @since JDK1.0
*/
public int search(int o)
{
int i = lastIndexOf(o);
if (i >= 0)
{
return size() - i;
}
return -1;
}
/**
* Returns clone of current IntStack
*
* @return clone of current IntStack
*/
public Object clone()
throws CloneNotSupportedException
{
return (IntStack) super.clone();
}
}
/**
* A very simple table that stores a list of int.
*
* This version is based on a "realloc" strategy -- a simle array is
* used, and when more storage is needed, a larger array is obtained
* and all existing data is recopied into it. As a result, read/write
* access to existing nodes is O(1) fast but appending may be O(N**2)
* slow. See also SuballocatedIntVector.
* @xsl.usage internal
*/
class IntVector implements Cloneable
{
/** Size of blocks to allocate */
protected int m_blocksize;
/** Array of ints */
protected int m_map[]; // IntStack is trying to see this directly
/** Number of ints in array */
protected int m_firstFree = 0;
/** Size of array */
protected int m_mapSize;
/**
* Default constructor. Note that the default
* block size is very small, for small lists.
*/
public IntVector()
{
m_blocksize = 32;
m_mapSize = m_blocksize;
m_map = new int[m_blocksize];
}
/**
* Construct a IntVector, using the given block size.
*
* @param blocksize Size of block to allocate
*/
public IntVector(int blocksize)
{
m_blocksize = blocksize;
m_mapSize = blocksize;
m_map = new int[blocksize];
}
/**
* Construct a IntVector, using the given block size.
*
* @param blocksize Size of block to allocate
*/
public IntVector(int blocksize, int increaseSize)
{
m_blocksize = increaseSize;
m_mapSize = blocksize;
m_map = new int[blocksize];
}
/**
* Copy constructor for IntVector
*
* @param v Existing IntVector to copy
*/
public IntVector(IntVector v)
{
m_map = new int[v.m_mapSize];
m_mapSize = v.m_mapSize;
m_firstFree = v.m_firstFree;
m_blocksize = v.m_blocksize;
System.arraycopy(v.m_map, 0, m_map, 0, m_firstFree);
}
/**
* Get the length of the list.
*
* @return length of the list
*/
public final int size()
{
return m_firstFree;
}
/**
* Get the length of the list.
*
* @return length of the list
*/
public final void setSize(int sz)
{
m_firstFree = sz;
}
/**
* Append a int onto the vector.
*
* @param value Int to add to the list
*/
public final void addElement(int value)
{
if ((m_firstFree + 1) >= m_mapSize)
{
m_mapSize += m_blocksize;
int newMap[] = new int[m_mapSize];
System.arraycopy(m_map, 0, newMap, 0, m_firstFree + 1);
m_map = newMap;
}
m_map[m_firstFree] = value;
m_firstFree++;
}
/**
* Append several int values onto the vector.
*
* @param value Int to add to the list
*/
public final void addElements(int value, int numberOfElements)
{
if ((m_firstFree + numberOfElements) >= m_mapSize)
{
m_mapSize += (m_blocksize+numberOfElements);
int newMap[] = new int[m_mapSize];
System.arraycopy(m_map, 0, newMap, 0, m_firstFree + 1);
m_map = newMap;
}
for (int i = 0; i < numberOfElements; i++)
{
m_map[m_firstFree] = value;
m_firstFree++;
}
}
/**
* Append several slots onto the vector, but do not set the values.
*
* @param numberOfElements Int to add to the list
*/
public final void addElements(int numberOfElements)
{
if ((m_firstFree + numberOfElements) >= m_mapSize)
{
m_mapSize += (m_blocksize+numberOfElements);
int newMap[] = new int[m_mapSize];
System.arraycopy(m_map, 0, newMap, 0, m_firstFree + 1);
m_map = newMap;
}
m_firstFree += numberOfElements;
}
/**
* Inserts the specified node in this vector at the specified index.
* Each component in this vector with an index greater or equal to
* the specified index is shifted upward to have an index one greater
* than the value it had previously.
*
* @param value Int to insert
* @param at Index of where to insert
*/
public final void insertElementAt(int value, int at)
{
if ((m_firstFree + 1) >= m_mapSize)
{
m_mapSize += m_blocksize;
int newMap[] = new int[m_mapSize];
System.arraycopy(m_map, 0, newMap, 0, m_firstFree + 1);
m_map = newMap;
}
if (at <= (m_firstFree - 1))
{
System.arraycopy(m_map, at, m_map, at + 1, m_firstFree - at);
}
m_map[at] = value;
m_firstFree++;
}
/**
* Inserts the specified node in this vector at the specified index.
* Each component in this vector with an index greater or equal to
* the specified index is shifted upward to have an index one greater
* than the value it had previously.
*/
public final void removeAllElements()
{
for (int i = 0; i < m_firstFree; i++)
{
m_map[i] = java.lang.Integer.MIN_VALUE;
}
m_firstFree = 0;
}
/**
* Removes the first occurrence of the argument from this vector.
* If the object is found in this vector, each component in the vector
* with an index greater or equal to the object's index is shifted
* downward to have an index one smaller than the value it had
* previously.
*
* @param s Int to remove from array
*
* @return True if the int was removed, false if it was not found
*/
public final boolean removeElement(int s)
{
for (int i = 0; i < m_firstFree; i++)
{
if (m_map[i] == s)
{
if ((i + 1) < m_firstFree)
System.arraycopy(m_map, i + 1, m_map, i - 1, m_firstFree - i);
else
m_map[i] = java.lang.Integer.MIN_VALUE;
m_firstFree--;
return true;
}
}
return false;
}
/**
* Deletes the component at the specified index. Each component in
* this vector with an index greater or equal to the specified
* index is shifted downward to have an index one smaller than
* the value it had previously.
*
* @param i index of where to remove and int
*/
public final void removeElementAt(int i)
{
if (i > m_firstFree)
System.arraycopy(m_map, i + 1, m_map, i, m_firstFree);
else
m_map[i] = java.lang.Integer.MIN_VALUE;
m_firstFree--;
}
/**
* Sets the component at the specified index of this vector to be the
* specified object. The previous component at that position is discarded.
*
* The index must be a value greater than or equal to 0 and less
* than the current size of the vector.
*
* @param value object to set
* @param index Index of where to set the object
*/
public final void setElementAt(int value, int index)
{
m_map[index] = value;
}
/**
* Get the nth element.
*
* @param i index of object to get
*
* @return object at given index
*/
public final int elementAt(int i)
{
return m_map[i];
}
/**
* Tell if the table contains the given node.
*
* @param s object to look for
*
* @return true if the object is in the list
*/
public final boolean contains(int s)
{
for (int i = 0; i < m_firstFree; i++)
{
if (m_map[i] == s)
return true;
}
return false;
}
/**
* Searches for the first occurence of the given argument,
* beginning the search at index, and testing for equality
* using the equals method.
*
* @param elem object to look for
* @param index Index of where to begin search
* @return the index of the first occurrence of the object
* argument in this vector at position index or later in the
* vector; returns -1 if the object is not found.
*/
public final int indexOf(int elem, int index)
{
for (int i = index; i < m_firstFree; i++)
{
if (m_map[i] == elem)
return i;
}
return java.lang.Integer.MIN_VALUE;
}
/**
* Searches for the first occurence of the given argument,
* beginning the search at index, and testing for equality
* using the equals method.
*
* @param elem object to look for
* @return the index of the first occurrence of the object
* argument in this vector at position index or later in the
* vector; returns -1 if the object is not found.
*/
public final int indexOf(int elem)
{
for (int i = 0; i < m_firstFree; i++)
{
if (m_map[i] == elem)
return i;
}
return java.lang.Integer.MIN_VALUE;
}
/**
* Searches for the first occurence of the given argument,
* beginning the search at index, and testing for equality
* using the equals method.
*
* @param elem Object to look for
* @return the index of the first occurrence of the object
* argument in this vector at position index or later in the
* vector; returns -1 if the object is not found.
*/
public final int lastIndexOf(int elem)
{
for (int i = (m_firstFree - 1); i >= 0; i--)
{
if (m_map[i] == elem)
return i;
}
return java.lang.Integer.MIN_VALUE;
}
/**
* Returns clone of current IntVector
*
* @return clone of current IntVector
*/
public Object clone()
throws CloneNotSupportedException
{
return new IntVector(this);
}
}
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