Java Hash Calculate hashSetSize(final int nrOfElements)

Description

Return a good value for creation of a hash set (to not resize) given a number of elements you wish to insert.

License

Apache License

Parameter

Parameter	Description
nrOfElements	Number of elements the set should be able to hold without resizing. Must be >= 0.

Return

Value to use for construction of the set.

Declaration

@SuppressWarnings("NumericCastThatLosesPrecision")
public static int hashSetSize(final int nrOfElements) 

Method Source Code

//package com.java2s;
/*//from   w  w  w . jav  a 2  s  .  c  o m
 * Copyright (C) 2012-2016. TomTom International BV (http://tomtom.com).
 *
 * 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.
 */

public class Main {
    public static final double LOAD_FACTOR = 0.75;

    /**
     * Return a good value for creation of a hash set (to not resize) given a number of elements you wish to insert.
     *
     * @param nrOfElements Number of elements the set should be able to hold without resizing. Must be >= 0.
     * @return Value to use for construction of the set.
     */
    @SuppressWarnings("NumericCastThatLosesPrecision")
    public static int hashSetSize(final int nrOfElements) {
        assert nrOfElements >= 0;
        return (int) Math.ceil(((double) nrOfElements) / LOAD_FACTOR);
    }
}

Related

1. hashOrNull(Object value)
2. hashOrZero(Object o)
3. hashPair(int a, int b)
4. hashpair(Object o1, Object o2)
5. hashPoint(int hashlength, double fraction)
6. hashThem(Object one, Object two)
7. hashToFloat(int x, int y, long seed)
8. hashToLong(final byte[] hash)
9. hashToName(long l)