IntTrie.java

/*
 * Copyright (C) 2008 Esmertec AG. Copyright (C) 2008 The Android Open Source
 * Project
 *
 * Licensed 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.
 */

package info.guardianproject.otr.app.im.app;

public class IntTrie {
    private Node mHead;

    class Node {
        private Node mFirstChild;
        private Node mNextSibling;
        private char mKey;
        int mValue;

        public final void add(String key, int value) {
            final int len = key.length();
            Node n = this;
            int index = 0;

            while (index < len) {
                n = n.getOrCreateNode(key.charAt(index++));
            }

            n.mValue = value;
        }

        private Node getOrCreateNode(char key) {
            for (Node n = mFirstChild; n != null; n = n.mNextSibling) {
                if (n.mKey == key) {
                    return n;
                }
            }

            Node n = new Node();

            n.mKey = key;
            n.mNextSibling = mFirstChild;
            mFirstChild = n;

            return n;
        }

        Node getNode(char key) {
            for (Node n = mFirstChild; n != null; n = n.mNextSibling) {
                if (n.mKey == key) {
                    return n;
                }
            }

            return null;
        }
    }

    public IntTrie(String[] dictionary, int[] values) {
        final int len = dictionary.length;

        if (len != values.length) {
            throw new IllegalArgumentException("dictionary[] and values[] must be the same length");
        }

        mHead = new Node();

        for (int i = 0; i < len; i++) {
            mHead.add(dictionary[i], values[i]);
        }
    }

    public Node getNode(char key) {
        return mHead.getNode(key);
    }
}