[927] | 1 | // Copyright 2012 Georg-August-Universität Göttingen, Germany
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| 2 | //
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| 3 | // Licensed under the Apache License, Version 2.0 (the "License");
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| 4 | // you may not use this file except in compliance with the License.
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| 5 | // You may obtain a copy of the License at
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| 6 | //
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| 7 | // http://www.apache.org/licenses/LICENSE-2.0
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| 8 | //
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| 9 | // Unless required by applicable law or agreed to in writing, software
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| 10 | // distributed under the License is distributed on an "AS IS" BASIS,
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| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| 12 | // See the License for the specific language governing permissions and
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| 13 | // limitations under the License.
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| 14 |
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[922] | 15 | package de.ugoe.cs.autoquest.usageprofiles;
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[518] | 16 |
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| 17 | import java.io.Serializable;
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| 18 | import java.util.Collection;
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| 19 | import java.util.LinkedHashSet;
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| 20 | import java.util.LinkedList;
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| 21 | import java.util.List;
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| 22 |
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| 23 | import de.ugoe.cs.util.StringTools;
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| 24 |
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| 25 | import edu.uci.ics.jung.graph.DelegateTree;
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| 26 | import edu.uci.ics.jung.graph.Graph;
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| 27 | import edu.uci.ics.jung.graph.Tree;
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| 28 |
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| 29 | /**
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| 30 | * <p>
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[559] | 31 | * This class implements a <it>trie</it>, i.e., a tree of sequences that the occurence of
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| 32 | * subsequences up to a predefined length. This length is the trie order.
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[518] | 33 | * </p>
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| 34 | *
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[1060] | 35 | * @author Steffen Herbold, Patrick Harms
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[518] | 36 | *
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| 37 | * @param <T>
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| 38 | * Type of the symbols that are stored in the trie.
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| 39 | *
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| 40 | * @see TrieNode
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| 41 | */
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| 42 | public class Trie<T> implements IDotCompatible, Serializable {
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| 43 |
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[559] | 44 | /**
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| 45 | * <p>
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| 46 | * Id for object serialization.
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| 47 | * </p>
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| 48 | */
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| 49 | private static final long serialVersionUID = 1L;
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[518] | 50 |
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[559] | 51 | /**
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| 52 | * <p>
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| 53 | * Collection of all symbols occuring in the trie.
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| 54 | * </p>
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| 55 | */
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[1251] | 56 | private SymbolMap<T, T> knownSymbols;
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[518] | 57 |
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[559] | 58 | /**
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| 59 | * <p>
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| 60 | * Reference to the root of the trie.
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| 61 | * </p>
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| 62 | */
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| 63 | private final TrieNode<T> rootNode;
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[518] | 64 |
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[559] | 65 | /**
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| 66 | * <p>
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[1060] | 67 | * Comparator to be used for comparing the symbols with each other
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[559] | 68 | * </p>
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| 69 | */
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[1189] | 70 | private SymbolComparator<T> comparator;
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[1060] | 71 |
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| 72 | /**
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| 73 | * <p>
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| 74 | * Contructor. Creates a new Trie with a {@link DefaultSymbolComparator}.
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| 75 | * </p>
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| 76 | */
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[559] | 77 | public Trie() {
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[1060] | 78 | this(new DefaultSymbolComparator<T>());
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| 79 | }
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| 80 |
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| 81 | /**
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| 82 | * <p>
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| 83 | * Contructor. Creates a new Trie with that uses a specific {@link SymbolComparator}.
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| 84 | * </p>
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| 85 | */
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| 86 | public Trie(SymbolComparator<T> comparator) {
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| 87 | this.comparator = comparator;
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| 88 | rootNode = new TrieNode<T>(comparator);
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[1251] | 89 | knownSymbols = new SymbolMap<T, T>(this.comparator);
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[559] | 90 | }
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[518] | 91 |
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[559] | 92 | /**
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| 93 | * <p>
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[1060] | 94 | * Copy-Constructor. Creates a new Trie as the copy of other. The other trie must not be null.
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[559] | 95 | * </p>
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| 96 | *
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| 97 | * @param other
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| 98 | * Trie that is copied
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| 99 | */
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| 100 | public Trie(Trie<T> other) {
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| 101 | if (other == null) {
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[766] | 102 | throw new IllegalArgumentException("other trie must not be null");
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[559] | 103 | }
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| 104 | rootNode = new TrieNode<T>(other.rootNode);
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[1251] | 105 | knownSymbols = new SymbolMap<T, T>(other.knownSymbols);
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[1060] | 106 | comparator = other.comparator;
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[559] | 107 | }
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[518] | 108 |
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[559] | 109 | /**
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| 110 | * <p>
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| 111 | * Returns a collection of all symbols occuring in the trie.
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| 112 | * </p>
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| 113 | *
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| 114 | * @return symbols occuring in the trie
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| 115 | */
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| 116 | public Collection<T> getKnownSymbols() {
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[1251] | 117 | return new LinkedHashSet<T>(knownSymbols.getSymbols());
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[559] | 118 | }
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[518] | 119 |
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[559] | 120 | /**
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| 121 | * <p>
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[1118] | 122 | * Trains the current trie using the given sequence and adds all subsequences of length
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[559] | 123 | * {@code maxOrder}.
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| 124 | * </p>
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| 125 | *
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| 126 | * @param sequence
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| 127 | * sequence whose subsequences are added to the trie
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| 128 | * @param maxOrder
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| 129 | * maximum length of the subsequences added to the trie
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| 130 | */
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| 131 | public void train(List<T> sequence, int maxOrder) {
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| 132 | if (maxOrder < 1) {
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| 133 | return;
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| 134 | }
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| 135 | IncompleteMemory<T> latestActions = new IncompleteMemory<T>(maxOrder);
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| 136 | int i = 0;
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| 137 | for (T currentEvent : sequence) {
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| 138 | latestActions.add(currentEvent);
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[1060] | 139 | addToKnownSymbols(currentEvent);
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[559] | 140 | i++;
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| 141 | if (i >= maxOrder) {
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| 142 | add(latestActions.getLast(maxOrder));
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| 143 | }
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| 144 | }
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| 145 | int sequenceLength = sequence.size();
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[1118] | 146 | int startIndex = Math.max(0, sequenceLength - maxOrder + 1);
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| 147 | for (int j = startIndex; j < sequenceLength; j++) {
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| 148 | add(sequence.subList(j, sequenceLength));
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[559] | 149 | }
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| 150 | }
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[518] | 151 |
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[559] | 152 | /**
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| 153 | * <p>
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[1251] | 154 | * Adds a given subsequence to the trie and increases the counters accordingly. NOTE: This
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| 155 | * method does not add the symbols to the list of known symbols. This is only ensured using
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| 156 | * the method {@link #train(List, int)}.
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[559] | 157 | * </p>
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| 158 | *
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| 159 | * @param subsequence
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| 160 | * subsequence whose counters are increased
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| 161 | * @see TrieNode#add(List)
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| 162 | */
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| 163 | protected void add(List<T> subsequence) {
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| 164 | if (subsequence != null && !subsequence.isEmpty()) {
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| 165 | subsequence = new LinkedList<T>(subsequence); // defensive copy!
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| 166 | T firstSymbol = subsequence.get(0);
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| 167 | TrieNode<T> node = getChildCreate(firstSymbol);
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| 168 | node.add(subsequence);
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| 169 | }
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| 170 | }
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[518] | 171 |
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[559] | 172 | /**
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| 173 | * <p>
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| 174 | * Returns the child of the root node associated with the given symbol or creates it if it does
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| 175 | * not exist yet.
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| 176 | * </p>
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| 177 | *
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| 178 | * @param symbol
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| 179 | * symbol whose node is required
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| 180 | * @return node associated with the symbol
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| 181 | * @see TrieNode#getChildCreate(Object)
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| 182 | */
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| 183 | protected TrieNode<T> getChildCreate(T symbol) {
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| 184 | return rootNode.getChildCreate(symbol);
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| 185 | }
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[518] | 186 |
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[559] | 187 | /**
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| 188 | * <p>
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| 189 | * Returns the child of the root node associated with the given symbol or null if it does not
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| 190 | * exist.
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| 191 | * </p>
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| 192 | *
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| 193 | * @param symbol
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| 194 | * symbol whose node is required
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| 195 | * @return node associated with the symbol; null if no such node exists
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| 196 | * @see TrieNode#getChild(Object)
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| 197 | */
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| 198 | protected TrieNode<T> getChild(T symbol) {
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| 199 | return rootNode.getChild(symbol);
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| 200 | }
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[518] | 201 |
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[559] | 202 | /**
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| 203 | * <p>
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| 204 | * Returns the number of occurences of the given sequence.
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| 205 | * </p>
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| 206 | *
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| 207 | * @param sequence
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| 208 | * sequence whose number of occurences is required
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| 209 | * @return number of occurences of the sequence
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| 210 | */
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| 211 | public int getCount(List<T> sequence) {
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| 212 | int count = 0;
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| 213 | TrieNode<T> node = find(sequence);
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| 214 | if (node != null) {
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| 215 | count = node.getCount();
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| 216 | }
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| 217 | return count;
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| 218 | }
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[518] | 219 |
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[559] | 220 | /**
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| 221 | * <p>
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| 222 | * Returns the number of occurences of the given prefix and a symbol that follows it.<br>
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| 223 | * Convenience function to simplify usage of {@link #getCount(List)}.
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| 224 | * </p>
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| 225 | *
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| 226 | * @param sequence
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| 227 | * prefix of the sequence
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| 228 | * @param follower
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| 229 | * suffix of the sequence
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| 230 | * @return number of occurences of the sequence
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| 231 | * @see #getCount(List)
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| 232 | */
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| 233 | public int getCount(List<T> sequence, T follower) {
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| 234 | List<T> tmpSequence = new LinkedList<T>(sequence);
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| 235 | tmpSequence.add(follower);
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| 236 | return getCount(tmpSequence);
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[518] | 237 |
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[559] | 238 | }
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[518] | 239 |
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[559] | 240 | /**
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| 241 | * <p>
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| 242 | * Searches the trie for a given sequence and returns the node associated with the sequence or
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| 243 | * null if no such node is found.
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| 244 | * </p>
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| 245 | *
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| 246 | * @param sequence
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| 247 | * sequence that is searched for
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| 248 | * @return node associated with the sequence
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| 249 | * @see TrieNode#find(List)
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| 250 | */
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| 251 | public TrieNode<T> find(List<T> sequence) {
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| 252 | if (sequence == null || sequence.isEmpty()) {
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| 253 | return rootNode;
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| 254 | }
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| 255 | List<T> sequenceCopy = new LinkedList<T>(sequence);
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| 256 | TrieNode<T> result = null;
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| 257 | TrieNode<T> node = getChild(sequenceCopy.get(0));
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| 258 | if (node != null) {
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| 259 | sequenceCopy.remove(0);
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| 260 | result = node.find(sequenceCopy);
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| 261 | }
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| 262 | return result;
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| 263 | }
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[518] | 264 |
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[559] | 265 | /**
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| 266 | * <p>
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| 267 | * Returns a collection of all symbols that follow a given sequence in the trie. In case the
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| 268 | * sequence is not found or no symbols follow the sequence the result will be empty.
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| 269 | * </p>
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| 270 | *
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| 271 | * @param sequence
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| 272 | * sequence whose followers are returned
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| 273 | * @return symbols following the given sequence
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| 274 | * @see TrieNode#getFollowingSymbols()
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| 275 | */
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| 276 | public Collection<T> getFollowingSymbols(List<T> sequence) {
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| 277 | Collection<T> result = new LinkedList<T>();
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| 278 | TrieNode<T> node = find(sequence);
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| 279 | if (node != null) {
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| 280 | result = node.getFollowingSymbols();
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| 281 | }
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| 282 | return result;
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| 283 | }
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[518] | 284 |
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[559] | 285 | /**
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| 286 | * <p>
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| 287 | * Returns the longest suffix of the given context that is contained in the tree and whose
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| 288 | * children are leaves.
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| 289 | * </p>
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| 290 | *
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| 291 | * @param context
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| 292 | * context whose suffix is searched for
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| 293 | * @return longest suffix of the context
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| 294 | */
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| 295 | public List<T> getContextSuffix(List<T> context) {
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| 296 | List<T> contextSuffix;
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| 297 | if (context != null) {
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| 298 | contextSuffix = new LinkedList<T>(context); // defensive copy
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| 299 | }
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| 300 | else {
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| 301 | contextSuffix = new LinkedList<T>();
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| 302 | }
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| 303 | boolean suffixFound = false;
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[518] | 304 |
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[559] | 305 | while (!suffixFound) {
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| 306 | if (contextSuffix.isEmpty()) {
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| 307 | suffixFound = true; // suffix is the empty word
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| 308 | }
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| 309 | else {
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| 310 | TrieNode<T> node = find(contextSuffix);
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| 311 | if (node != null) {
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| 312 | if (!node.getFollowingSymbols().isEmpty()) {
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| 313 | suffixFound = true;
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| 314 | }
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| 315 | }
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| 316 | if (!suffixFound) {
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| 317 | contextSuffix.remove(0);
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| 318 | }
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| 319 | }
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| 320 | }
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[518] | 321 |
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[559] | 322 | return contextSuffix;
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| 323 | }
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[1118] | 324 |
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| 325 | /**
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[1186] | 326 | * <p>
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| 327 | * used to recursively process the trie. The provided processor will be called for any path
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| 328 | * through the tree. The processor may abort the processing through returns values of its
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| 329 | * {@link TrieProcessor#process(List, int)} method.
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| 330 | * </p>
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[1118] | 331 | *
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[1186] | 332 | * @param processor the processor to process the tree
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[1118] | 333 | */
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| 334 | public void process(TrieProcessor<T> processor) {
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| 335 | LinkedList<T> context = new LinkedList<T>();
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| 336 |
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| 337 | for (TrieNode<T> child : rootNode.getChildren()) {
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| 338 | if (!process(context, child, processor)) {
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| 339 | break;
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| 340 | }
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| 341 | }
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| 342 | }
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[518] | 343 |
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[559] | 344 | /**
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| 345 | * <p>
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[1186] | 346 | * processes a specific path by calling the provided processor. Furthermore, the method
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| 347 | * calls itself recursively for further subpaths.
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[1118] | 348 | * </p>
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[1186] | 349 | *
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| 350 | * @param context the context of the currently processed trie node, i.e. the preceeding
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| 351 | * symbols
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| 352 | * @param child the processed trie node
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| 353 | * @param processor the processor used for processing the trie
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| 354 | *
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| 355 | * @return true, if processing shall continue, false else
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[1118] | 356 | */
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| 357 | private boolean process(LinkedList<T> context,
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| 358 | TrieNode<T> node,
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| 359 | TrieProcessor<T> processor)
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| 360 | {
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| 361 | context.add(node.getSymbol());
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| 362 |
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| 363 | TrieProcessor.Result result = processor.process(context, node.getCount());
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| 364 |
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| 365 | if (result == TrieProcessor.Result.CONTINUE) {
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| 366 | for (TrieNode<T> child : node.getChildren()) {
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| 367 | if (!process(context, child, processor)) {
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| 368 | break;
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| 369 | }
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| 370 | }
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| 371 | }
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| 372 |
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| 373 | context.removeLast();
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| 374 |
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| 375 | return result != TrieProcessor.Result.BREAK;
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| 376 | }
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| 377 |
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| 378 | /**
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| 379 | * <p>
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[1110] | 380 | * returns a list of symbol sequences which have a minimal length and that occurred as often
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| 381 | * as defined by the given occurrence count. If the given occurrence count is smaller 1 then
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| 382 | * those sequences are returned, that occur most often. The resulting list is empty, if there
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| 383 | * is no symbol sequence with the minimal length or the provided number of occurrences.
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[1060] | 384 | * </p>
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| 385 | *
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[1110] | 386 | * @param minimalLength the minimal length of the returned sequences
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| 387 | * @param occurrenceCount the number of occurrences of the returned sequences
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[1060] | 388 | *
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| 389 | * @return as described
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| 390 | */
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[1110] | 391 | public Collection<List<T>> getSequencesWithOccurrenceCount(int minimalLength,
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| 392 | int occurrenceCount)
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| 393 | {
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[1060] | 394 | LinkedList<TrieNode<T>> context = new LinkedList<TrieNode<T>>();
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| 395 | Collection<List<TrieNode<T>>> paths = new LinkedList<List<TrieNode<T>>>();
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| 396 |
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| 397 | context.push(rootNode);
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| 398 |
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[1110] | 399 | // traverse the trie and determine all sequences, which have the provided number of
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[1060] | 400 | // occurrences and a minimal length.
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| 401 |
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| 402 | // minimalLength + 1 because we denote the depth including the root node
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[1110] | 403 | determineLongPathsWithMostOccurrences(minimalLength + 1, occurrenceCount, paths, context);
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[1060] | 404 |
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| 405 | Collection<List<T>> resultingPaths = new LinkedList<List<T>>();
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| 406 | List<T> resultingPath;
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| 407 |
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| 408 | if (paths.size() > 0) {
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| 409 |
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| 410 | for (List<TrieNode<T>> path : paths) {
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| 411 | resultingPath = new LinkedList<T>();
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| 412 |
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| 413 | for (TrieNode<T> node : path) {
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| 414 | if (node.getSymbol() != null) {
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| 415 | resultingPath.add(node.getSymbol());
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| 416 | }
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| 417 | }
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| 418 |
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| 419 | resultingPaths.add(resultingPath);
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| 420 | }
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| 421 | }
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| 422 |
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| 423 | return resultingPaths;
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| 424 | }
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| 425 |
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| 426 | /**
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| 427 | * <p>
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[1110] | 428 | * Traverses the trie to collect all sequences with a defined number of occurrences and with
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| 429 | * a minimal length. If the given occurrence count is smaller 1 then those sequences are
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| 430 | * searched that occur most often. The length of the sequences is encoded in the provided
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| 431 | * recursion depth.
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[1060] | 432 | * </p>
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| 433 | *
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[1110] | 434 | * @param minimalDepth the minimal recursion depth to be done
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| 435 | * @param occurrenceCount the number of occurrences of the returned sequences
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| 436 | * @param paths the paths through the trie that all occurred with the same amount
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| 437 | * (if occurrence count is smaller 1, the paths which occurred most
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| 438 | * often) and that have the so far found matching number of occurrences
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| 439 | * (is updated each time a further path with the same number of
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| 440 | * occurrences is found; if occurrence count is smaller 1
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| 441 | * it is replaced if a path with more occurrences is found)
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| 442 | * @param context the path through the trie, that is analyzed by the recursive call
|
---|
[1060] | 443 | */
|
---|
| 444 | private void determineLongPathsWithMostOccurrences(int minimalDepth,
|
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[1110] | 445 | int occurrenceCount,
|
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[1060] | 446 | Collection<List<TrieNode<T>>> paths,
|
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| 447 | LinkedList<TrieNode<T>> context)
|
---|
| 448 | {
|
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[1110] | 449 | int envisagedCount = occurrenceCount;
|
---|
[1060] | 450 |
|
---|
| 451 | // only if we already reached the depth to be achieved, we check if the paths have the
|
---|
[1110] | 452 | // required number of occurrences
|
---|
[1060] | 453 | if (context.size() >= minimalDepth) {
|
---|
| 454 |
|
---|
[1110] | 455 | if (envisagedCount < 1) {
|
---|
| 456 | // try to determine the maximum number of occurrences so far, if any
|
---|
| 457 | if (paths.size() > 0) {
|
---|
| 458 | List<TrieNode<T>> path = paths.iterator().next();
|
---|
| 459 | envisagedCount = path.get(path.size() - 1).getCount();
|
---|
| 460 | }
|
---|
[1060] | 461 |
|
---|
[1110] | 462 | // if the current path has a higher number of occurrences than all so far, clear
|
---|
| 463 | // the paths collected so far and set the new number of occurrences as new maximum
|
---|
| 464 | if (context.getLast().getCount() > envisagedCount) {
|
---|
| 465 | paths.clear();
|
---|
| 466 | envisagedCount = context.getLast().getCount();
|
---|
| 467 | }
|
---|
[1060] | 468 | }
|
---|
| 469 |
|
---|
| 470 | // if the path matches the current maximal number of occurrences, add it to the list
|
---|
| 471 | // of collected paths with these number of occurrences
|
---|
[1110] | 472 | if (context.getLast().getCount() == envisagedCount) {
|
---|
[1060] | 473 | paths.add(new LinkedList<TrieNode<T>>(context));
|
---|
| 474 | }
|
---|
| 475 | }
|
---|
| 476 |
|
---|
| 477 | // perform the trie traversal
|
---|
| 478 | for (TrieNode<T> child : context.getLast().getChildren()) {
|
---|
[1110] | 479 | if (child.getCount() >= envisagedCount) {
|
---|
[1060] | 480 | context.add(child);
|
---|
[1110] | 481 | determineLongPathsWithMostOccurrences
|
---|
| 482 | (minimalDepth, occurrenceCount, paths, context);
|
---|
[1060] | 483 | context.removeLast();
|
---|
| 484 | }
|
---|
| 485 | }
|
---|
| 486 | }
|
---|
| 487 |
|
---|
| 488 | /**
|
---|
| 489 | * <p>
|
---|
| 490 | * adds a new symbol to the collection of known symbols if this symbol is not already
|
---|
| 491 | * contained. The symbols are compared using the comparator.
|
---|
| 492 | * </p>
|
---|
| 493 | *
|
---|
| 494 | * @param symbol the symbol to be added to the known symbols
|
---|
| 495 | */
|
---|
| 496 | private void addToKnownSymbols(T symbol) {
|
---|
[1251] | 497 | if (!knownSymbols.containsSymbol(symbol)) {
|
---|
| 498 | knownSymbols.addSymbol(symbol, symbol);
|
---|
[1060] | 499 | }
|
---|
| 500 | }
|
---|
| 501 |
|
---|
| 502 | /**
|
---|
| 503 | * <p>
|
---|
[559] | 504 | * Helper class for graph visualization of a trie.
|
---|
| 505 | * </p>
|
---|
| 506 | *
|
---|
| 507 | * @author Steffen Herbold
|
---|
| 508 | * @version 1.0
|
---|
| 509 | */
|
---|
| 510 | static public class Edge {}
|
---|
[518] | 511 |
|
---|
[559] | 512 | /**
|
---|
| 513 | * <p>
|
---|
| 514 | * Helper class for graph visualization of a trie.
|
---|
| 515 | * </p>
|
---|
| 516 | *
|
---|
| 517 | * @author Steffen Herbold
|
---|
| 518 | * @version 1.0
|
---|
| 519 | */
|
---|
| 520 | static public class TrieVertex {
|
---|
[518] | 521 |
|
---|
[559] | 522 | /**
|
---|
| 523 | * <p>
|
---|
| 524 | * Id of the vertex.
|
---|
| 525 | * </p>
|
---|
| 526 | */
|
---|
| 527 | private String id;
|
---|
[518] | 528 |
|
---|
[559] | 529 | /**
|
---|
| 530 | * <p>
|
---|
| 531 | * Contructor. Creates a new TrieVertex.
|
---|
| 532 | * </p>
|
---|
| 533 | *
|
---|
| 534 | * @param id
|
---|
| 535 | * id of the vertex
|
---|
| 536 | */
|
---|
| 537 | protected TrieVertex(String id) {
|
---|
| 538 | this.id = id;
|
---|
| 539 | }
|
---|
[518] | 540 |
|
---|
[559] | 541 | /**
|
---|
| 542 | * <p>
|
---|
| 543 | * Returns the id of the vertex.
|
---|
| 544 | * </p>
|
---|
| 545 | *
|
---|
| 546 | * @see java.lang.Object#toString()
|
---|
| 547 | */
|
---|
| 548 | @Override
|
---|
| 549 | public String toString() {
|
---|
| 550 | return id;
|
---|
| 551 | }
|
---|
| 552 | }
|
---|
[518] | 553 |
|
---|
[559] | 554 | /**
|
---|
| 555 | * <p>
|
---|
| 556 | * Returns a {@link Graph} representation of the trie.
|
---|
| 557 | * </p>
|
---|
| 558 | *
|
---|
| 559 | * @return {@link Graph} representation of the trie
|
---|
| 560 | */
|
---|
| 561 | protected Tree<TrieVertex, Edge> getGraph() {
|
---|
| 562 | DelegateTree<TrieVertex, Edge> graph = new DelegateTree<TrieVertex, Edge>();
|
---|
| 563 | rootNode.getGraph(null, graph);
|
---|
| 564 | return graph;
|
---|
| 565 | }
|
---|
[518] | 566 |
|
---|
[559] | 567 | /*
|
---|
| 568 | * (non-Javadoc)
|
---|
| 569 | *
|
---|
[922] | 570 | * @see de.ugoe.cs.autoquest.usageprofiles.IDotCompatible#getDotRepresentation()
|
---|
[559] | 571 | */
|
---|
| 572 | public String getDotRepresentation() {
|
---|
| 573 | StringBuilder stringBuilder = new StringBuilder();
|
---|
| 574 | stringBuilder.append("digraph model {" + StringTools.ENDLINE);
|
---|
| 575 | rootNode.appendDotRepresentation(stringBuilder);
|
---|
| 576 | stringBuilder.append('}' + StringTools.ENDLINE);
|
---|
| 577 | return stringBuilder.toString();
|
---|
| 578 | }
|
---|
[518] | 579 |
|
---|
[559] | 580 | /**
|
---|
| 581 | * <p>
|
---|
| 582 | * Returns the string representation of the root node.
|
---|
| 583 | * </p>
|
---|
| 584 | *
|
---|
| 585 | * @see TrieNode#toString()
|
---|
| 586 | * @see java.lang.Object#toString()
|
---|
| 587 | */
|
---|
| 588 | @Override
|
---|
| 589 | public String toString() {
|
---|
| 590 | return rootNode.toString();
|
---|
| 591 | }
|
---|
[518] | 592 |
|
---|
[559] | 593 | /**
|
---|
| 594 | * <p>
|
---|
| 595 | * Returns the number of symbols contained in the trie.
|
---|
| 596 | * </p>
|
---|
| 597 | *
|
---|
| 598 | * @return number of symbols contained in the trie
|
---|
| 599 | */
|
---|
| 600 | public int getNumSymbols() {
|
---|
| 601 | return knownSymbols.size();
|
---|
| 602 | }
|
---|
[518] | 603 |
|
---|
[559] | 604 | /**
|
---|
| 605 | * <p>
|
---|
| 606 | * Returns the number of trie nodes that are ancestors of a leaf. This is the equivalent to the
|
---|
| 607 | * number of states a first-order markov model would have.
|
---|
| 608 | * <p>
|
---|
| 609 | *
|
---|
| 610 | * @return number of trie nodes that are ancestors of leafs.
|
---|
| 611 | */
|
---|
| 612 | public int getNumLeafAncestors() {
|
---|
| 613 | List<TrieNode<T>> ancestors = new LinkedList<TrieNode<T>>();
|
---|
| 614 | rootNode.getLeafAncestors(ancestors);
|
---|
| 615 | return ancestors.size();
|
---|
| 616 | }
|
---|
[518] | 617 |
|
---|
[559] | 618 | /**
|
---|
| 619 | * <p>
|
---|
| 620 | * Returns the number of trie nodes that are leafs.
|
---|
| 621 | * </p>
|
---|
| 622 | *
|
---|
| 623 | * @return number of leafs in the trie
|
---|
| 624 | */
|
---|
| 625 | public int getNumLeafs() {
|
---|
| 626 | return rootNode.getNumLeafs();
|
---|
| 627 | }
|
---|
[518] | 628 |
|
---|
[559] | 629 | /**
|
---|
| 630 | * <p>
|
---|
| 631 | * Updates the list of known symbols by replacing it with all symbols that are found in the
|
---|
| 632 | * child nodes of the root node. This should be the same as all symbols that are contained in
|
---|
| 633 | * the trie.
|
---|
| 634 | * </p>
|
---|
| 635 | */
|
---|
| 636 | public void updateKnownSymbols() {
|
---|
[1251] | 637 | knownSymbols = new SymbolMap<T, T>(this.comparator);
|
---|
[559] | 638 | for (TrieNode<T> node : rootNode.getChildren()) {
|
---|
[1060] | 639 | addToKnownSymbols(node.getSymbol());
|
---|
[559] | 640 | }
|
---|
| 641 | }
|
---|
[518] | 642 |
|
---|
[559] | 643 | /**
|
---|
| 644 | * <p>
|
---|
| 645 | * Two Tries are defined as equal, if their {@link #rootNode} are equal.
|
---|
| 646 | * </p>
|
---|
| 647 | *
|
---|
| 648 | * @see java.lang.Object#equals(java.lang.Object)
|
---|
| 649 | */
|
---|
| 650 | @SuppressWarnings("rawtypes")
|
---|
| 651 | @Override
|
---|
| 652 | public boolean equals(Object other) {
|
---|
| 653 | if (other == this) {
|
---|
| 654 | return true;
|
---|
| 655 | }
|
---|
| 656 | if (other instanceof Trie) {
|
---|
| 657 | return rootNode.equals(((Trie) other).rootNode);
|
---|
| 658 | }
|
---|
| 659 | return false;
|
---|
| 660 | }
|
---|
| 661 |
|
---|
| 662 | /*
|
---|
| 663 | * (non-Javadoc)
|
---|
| 664 | *
|
---|
| 665 | * @see java.lang.Object#hashCode()
|
---|
| 666 | */
|
---|
| 667 | @Override
|
---|
| 668 | public int hashCode() {
|
---|
| 669 | int multiplier = 17;
|
---|
| 670 | int hash = 42;
|
---|
| 671 | if (rootNode != null) {
|
---|
| 672 | hash = multiplier * hash + rootNode.hashCode();
|
---|
| 673 | }
|
---|
| 674 | return hash;
|
---|
| 675 | }
|
---|
[1060] | 676 |
|
---|
[518] | 677 | }
|
---|