Java BigInteger Create toBigInteger(int[] x, int bitsPerDigit)

Description

to Big Integer

License

Apache License

Declaration

static BigInteger toBigInteger(int[] x, int bitsPerDigit) 

Method Source Code

//package com.java2s;
/**//  ww w . j a  v a2  s . c o  m
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.math.BigInteger;

public class Main {
    static BigInteger toBigInteger(int[] x, int bitsPerDigit) {
        final int digitsPerLong = (59 / bitsPerDigit) + 1;
        BigInteger c = BigInteger.ZERO;
        for (int i = 0; i < x.length;) {
            long a = 0;
            for (int j = 0; i < x.length && j < digitsPerLong; j++) {
                a |= ((long) x[i] << (bitsPerDigit * j));
                i++;
            }
            c = c.add(BigInteger.valueOf(a).shiftLeft(bitsPerDigit * digitsPerLong * ((i - 1) / digitsPerLong)));
        }
        return c;
    }
}

Related

1. toBigInteger(final byte[] array, final int offset, final int length)
2. toBigInteger(final byte[] buffer, final int offset, final int length)
3. toBigInteger(final byte[] bytes)
4. toBigInteger(final Integer i)
5. toBigInteger(int arg)
6. toBigInteger(List integerVector)
7. toBigInteger(long value)
8. toBigInteger(Object o)
9. toBigInteger(Object value)