Java ListIterator Usage stringCrossJoin(List> candidates)

Description

string Cross Join

License

Apache License

Declaration

private static List<String> stringCrossJoin(List<Set<String>> candidates) 

Method Source Code

//package com.java2s;
/**/*from   w  ww. ja va2  s .  co  m*/
 * Copyright 2011-2017 Asakusa Framework Team.
 *
 * 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.
 */

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;
import java.util.ListIterator;

import java.util.Set;

public class Main {
    private static List<String> stringCrossJoin(List<Set<String>> candidates) {
        assert candidates != null;
        assert candidates.isEmpty() == false;
        List<String> results = new ArrayList<>();
        Iterator<Set<String>> iter = candidates.iterator();
        assert iter.hasNext();
        results.addAll(iter.next());
        while (iter.hasNext()) {
            Set<String> next = iter.next();
            if (next.size() == 1) {
                String suffix = next.iterator().next();
                for (ListIterator<String> i = results.listIterator(); i.hasNext();) {
                    String vaule = i.next();
                    i.set(vaule + suffix);
                }
            } else {
                List<String> nextResults = new ArrayList<>();
                for (String value : results) {
                    for (String suffix : next) {
                        nextResults.add(value + suffix);
                    }
                }
                results = nextResults;
            }
        }
        return results;
    }
}

Related

1. removeStartsWith(String prefix, List lines)
2. reset(ListIterator iterator)
3. retainAll(final List list, final Collection indices)
4. rewindIterator( @SuppressWarnings("rawtypes") ListIterator it, int n)
5. sort(List aList)
6. stringToList(String commas)
7. stripQuotes(List input)
8. toArray(List a)
9. toCFML(Object obj)