Java tutorial
/* * 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: IntVector.java 468655 2006-10-28 07:12:06Z minchau $ */ /** * 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 */ public 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); } }