Java Set Cardinality cardinality(long v)

Description

Compute the cardinality (number of set bits)

License

Open Source License

Parameter

Parameter	Description
v	Value

Return

Number of bits set in long

Declaration

public static int cardinality(long v) 

Method Source Code

//package com.java2s;
/*//from  w w  w. j  a  v a2 s  .co  m
 This file is part of ELKI:
 Environment for Developing KDD-Applications Supported by Index-Structures
    
 Copyright (C) 2014
 Ludwig-Maximilians-Universit?t M?nchen
 Lehr- und Forschungseinheit f?r Datenbanksysteme
 ELKI Development Team
    
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Affero 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 Affero General Public License for more details.
    
 You should have received a copy of the GNU Affero General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

public class Main {
    /**
     * Compute the cardinality (number of set bits)
     * 
     * @param v Value
     * @return Number of bits set in long
     */
    public static int cardinality(long v) {
        return Long.bitCount(v);
    }

    /**
     * Compute the cardinality (number of set bits)
     * 
     * Low-endian layout for the array.
     * 
     * @param v Value
     * @return Number of bits set in long[]
     */
    public static int cardinality(long[] v) {
        int sum = 0;
        for (int i = 0; i < v.length; i++) {
            sum += Long.bitCount(v[i]);
        }
        return sum;
    }
}

Related

1. cardinality(byte b)
2. cardinality(final int from, final int to, final long[] words)
3. cardinalityInBitmapRange(long[] bitmap, int start, int end)
4. cardinalityInBitmapWordRange(long[] bitmap, int start, int end)