/**
*
* Copyright (c) 2006-2017, Speedment, Inc. All Rights Reserved.
*
* 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 com.speedment.common.combinatorics;
import com.speedment.common.combinatorics.internal.PermutationUtil;
import java.util.*;
import java.util.stream.Stream;
/**
* General Permutation support from
* http://minborgsjavapot.blogspot.com/2015/07/java-8-master-permutations.html
*
* @author Per Minborg
*/
public final class Permutation {
public static long factorial(final int n) {
return PermutationUtil.factorial(n);
}
public static <T> List<T> permutation(final long no, final List<T> items) {
return PermutationUtil.permutation(no, items);
}
@SafeVarargs
@SuppressWarnings("varargs") // Creating a List from an array is safe
public static <T> Stream<Stream<T>> of(final T... items) {
return PermutationUtil.of(items);
}
private Permutation() {
throw new UnsupportedOperationException();
}
}