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 * 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
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 * 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.
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package org.apache.commons.collections4.trie;

import java.util.Map;

import org.apache.commons.collections4.trie.analyzer.StringKeyAnalyzer;

Implementation of a PATRICIA Trie (Practical Algorithm to Retrieve Information
Coded in Alphanumeric).
 A PATRICIA Trie is a compressed Trie. Instead of storing all data at the edges of the Trie (and having empty internal nodes), PATRICIA stores data in every node. This allows for very efficient traversal, insert, delete, predecessor, successor, prefix, range, and AbstractPatriciaTrie.select(Object) operations. All operations are performed at worst in O(K) time, where K is the number of bits in the largest item in the tree. In practice, operations actually take O(A(K)) time, where A(K) is the average number of bits of all items in the tree. 

Most importantly, PATRICIA requires very few comparisons to keys while
doing any operation. While performing a lookup, each comparison (at most
K of them, described above) will perform a single bit comparison against
the given key, instead of comparing the entire key to another key.

 The Trie can return operations in lexicographical order using the 'prefixMap', 'submap', or 'iterator' methods. The Trie can also scan for items that are 'bitwise' (using an XOR metric) by the 'select' method. Bitwise closeness is determined by the KeyAnalyzer returning true or false for a bit being set or not in a given key. 
 This PATRICIA Trie supports both variable length & fixed length keys. Some methods, such as AbstractPatriciaTrie.prefixMap(Object) are suited only to variable length keys. 
Type parameters:
<E> – the type of the values in this map
See Also:
Radix Tree
PATRICIA
Crit-Bit Tree
Since:
4.0/**
 * Implementation of a PATRICIA Trie (Practical Algorithm to Retrieve Information
 * Coded in Alphanumeric).
 * <p>
 * A PATRICIA {@link org.apache.commons.collections4.Trie} is a compressed
 * {@link org.apache.commons.collections4.Trie}. Instead of storing
 * all data at the edges of the {@link org.apache.commons.collections4.Trie}
 * (and having empty internal nodes), PATRICIA stores data in every node.
 * This allows for very efficient traversal, insert, delete, predecessor,
 * successor, prefix, range, and {@link #select(Object)}
 * operations. All operations are performed at worst in O(K) time, where K
 * is the number of bits in the largest item in the tree. In practice,
 * operations actually take O(A(K)) time, where A(K) is the average number of
 * bits of all items in the tree.
 * </p>
 * <p>
 * Most importantly, PATRICIA requires very few comparisons to keys while
 * doing any operation. While performing a lookup, each comparison (at most
 * K of them, described above) will perform a single bit comparison against
 * the given key, instead of comparing the entire key to another key.
 * </p>
 * <p>
 * The {@link org.apache.commons.collections4.Trie} can return operations in
 * lexicographical order using the 'prefixMap', 'submap', or 'iterator' methods.
 * The {@link org.apache.commons.collections4.Trie} can also
 * scan for items that are 'bitwise' (using an XOR metric) by the 'select' method.
 * Bitwise closeness is determined by the {@link KeyAnalyzer} returning true or
 * false for a bit being set or not in a given key.
 * </p>
 * <p>
 * This PATRICIA {@link org.apache.commons.collections4.Trie} supports both variable
 * length &amp; fixed length keys. Some methods, such as {@link #prefixMap(Object)}
 * are suited only to variable length keys.
 * </p>
 *
 * @param <E> the type of the values in this map
 *
 * @see <a href="http://en.wikipedia.org/wiki/Radix_tree">Radix Tree</a>
 * @see <a href="http://www.csse.monash.edu.au/~lloyd/tildeAlgDS/Tree/PATRICIA">PATRICIA</a>
 * @see <a href="http://www.imperialviolet.org/binary/critbit.pdf">Crit-Bit Tree</a>
 * @since 4.0
 */
public class PatriciaTrie<E> extends AbstractPatriciaTrie<String, E> {

    private static final long serialVersionUID = 4446367780901817838L;

    public PatriciaTrie() {
        super(new StringKeyAnalyzer());
    }

    public PatriciaTrie(final Map<? extends String, ? extends E> m) {
        super(new StringKeyAnalyzer(), m);
    }

}