Java BitSet asArrayWith0s(int max, BitSet bits)

Description

gets an array in which the i-th component has value i, if and only if i is contained in bits

License

Open Source License

Parameter

Parameter	Description
max	maximum value
bits	a parameter

Return

values and 0s

Declaration

public static int[] asArrayWith0s(int max, BitSet bits) 

Method Source Code

//package com.java2s;
/*//  w  ww  .  j  a  v  a2 s.  c  o  m
 * BitSetUtils.java Copyright (C) 2019. Daniel H. Huson
 *
 *  (Some files contain contributions from other authors, who are then mentioned separately.)
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

import java.util.BitSet;

import java.util.Iterator;

public class Main {
    /**
     * gets an array in which the i-th component has value i, if and only if i is contained in bits
     *
     * @param max  maximum value
     * @param bits
     * @return values and 0s
     */
    public static int[] asArrayWith0s(int max, BitSet bits) {
        final int[] array = new int[max + 1];
        for (Integer t : members(bits))
            array[t] = t;
        return array;
    }

    /**
     * iterable over all members
     *
     * @param set
     * @return members
     */
    public static Iterable<Integer> members(BitSet set) {
        return () -> new Iterator<Integer>() {
            private int i = set.nextSetBit(0);

            @Override
            public boolean hasNext() {
                return i != -1;
            }

            @Override
            public Integer next() {
                int result = i;
                i = set.nextSetBit(i + 1);
                return result;
            }
        };
    }
}

Related

1. binaryStringToBitSet(String stringRepresentation)
2. binaryToGray(BitSet binary)
3. bitsetCopy(BitSet src, int srcOffset, BitSet dest, int destOffset, int length)
4. bitSetTest(BitSet bitSet, int index)