net.automatalib.util.tries.SharedSuffixTrie Maven / Gradle / Ivy
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This artifact provides various common utility operations for analyzing and manipulating
automata and graphs, such as traversal, minimization and copying.
/* Copyright (C) 2013 TU Dortmund
* This file is part of AutomataLib, http://www.automatalib.net/.
*
* AutomataLib is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 3.0 as published by the Free Software Foundation.
*
* AutomataLib is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with AutomataLib; if not, see
* http://www.gnu.de/documents/lgpl.en.html.
*/
package net.automatalib.util.tries;
import net.automatalib.words.Alphabet;
public class SharedSuffixTrie extends SuffixTrie {
private final Alphabet alphabet;
public SharedSuffixTrie(Alphabet alphabet) {
super(new SharedSuffixTrieNode());
this.alphabet = alphabet;
}
public SharedSuffixTrie(Alphabet alphabet, boolean graphRepresentable) {
super(graphRepresentable, new SharedSuffixTrieNode());
this.alphabet = alphabet;
}
/* (non-Javadoc)
* @see net.automatalib.util.tries.SuffixTrie#add(java.lang.Object, net.automatalib.util.tries.SuffixTrieNode)
*/
@Override
@SuppressWarnings("unchecked")
public SuffixTrieNode add(I symbol, SuffixTrieNode parent) {
if(parent.getClass() != SharedSuffixTrieNode.class) {
throw new IllegalArgumentException("Invalid suffix trie node");
}
int symbolIdx = alphabet.getSymbolIndex(symbol);
SharedSuffixTrieNode sparent = (SharedSuffixTrieNode)parent;
SharedSuffixTrieNode child;
SharedSuffixTrieNode[] children = sparent.children;
if(children == null) {
children = sparent.children = new SharedSuffixTrieNode[alphabet.size()];
}
else if((child = children[symbolIdx]) != null) {
return child;
}
child = new SharedSuffixTrieNode<>(symbol, sparent);
children[symbolIdx] = child;
return child;
}
}