/*
* 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.
*/
/*
* Imported from Apache Harmony CG 20060208, based on revision 575306.
* I have reverted the TLS stuff to hard-coded strings.
*/
package java.math;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Random;
import java.io.Serializable;
public class BigInteger extends Number implements Comparable, Serializable {
private static final long serialVersionUID = -8287574255936472291L;
/* Fields used for the internal representation. */
/** The magnitude of this in the little-endian representation. */
transient int digits[];
/** The length of this in measured in ints. Can be less than digits.length(). */
transient int numberLength;
/** The sign of this. */
transient int sign;
public static final BigInteger ONE = new BigInteger(1, 1);
/*
** [CG 20080209] Only part of public API since 1.5
** Needed by Multiplication, so we make it package-visible.
*/
static final BigInteger TEN = new BigInteger(1, 10);
public static final BigInteger ZERO = new BigInteger(0, 0);
/** The {@code BigInteger} constant -1. */
static final BigInteger MINUS_ONE = new BigInteger(-1, 1);
/** The {@code BigInteger} constant 0 used for comparison. */
static final int EQUALS = 0;
/** The {@code BigInteger} constant 1 used for comparison. */
static final int GREATER = 1;
/** The {@code BigInteger} constant -1 used for comparison. */
static final int LESS = -1;
/** All the {@ BigInteger} numbers in the range [0,10] are cached. */
static final BigInteger[] SMALL_VALUES = { ZERO, ONE, new BigInteger(1, 2),
new BigInteger(1, 3), new BigInteger(1, 4), new BigInteger(1, 5),
new BigInteger(1, 6), new BigInteger(1, 7), new BigInteger(1, 8),
new BigInteger(1, 9), TEN };
private transient int firstNonzeroDigit = -2;
/* Serialized Fields */
private int signum;
private byte[] magnitude;
private transient int hashCode = 0;
/* Public Constructors */
public BigInteger(int numBits, Random rnd) {
if (numBits < 0) {
throw new IllegalArgumentException("numBits must be non-negative");
}
if (numBits == 0) {
sign = 0;
numberLength = 1;
digits = new int[] { 0 };
} else {
sign = 1;
numberLength = (numBits + 31) >> 5;
digits = new int[numberLength];
for (int i = 0; i < numberLength; i++) {
digits[i] = rnd.nextInt();
}
// Using only the necessary bits
digits[numberLength - 1] >>>= (-numBits) & 31;
cutOffLeadingZeroes();
}
}
public BigInteger(int bitLength, int certainty, Random rnd) {
if (bitLength < 2) {
throw new ArithmeticException("bitLength < 2");
}
BigInteger me = Primality.consBigInteger(bitLength, certainty, rnd);
sign = me.sign;
numberLength = me.numberLength;
digits = me.digits;
}
public BigInteger(String val) {
this(val, 10);
}
public BigInteger(String val, int radix) {
if (val == null) {
throw new NullPointerException();
}
if ((radix < Character.MIN_RADIX) || (radix > Character.MAX_RADIX)) {
throw new NumberFormatException("Radix out of range");
}
if (val.length() == 0) {
throw new NumberFormatException("Zero length BigInteger");
}
setFromString(this, val, radix);
}
public BigInteger(int signum, byte[] magnitude) {
if (magnitude == null) {
throw new NullPointerException();
}
if ((signum < -1) || (signum > 1)) {
throw new NumberFormatException("Invalid signum value");
}
if (signum == 0) {
// [CG 20080208] WAS: for (byte element : magnitude) {
for (int i = 0; i < magnitude.length; ++i) {
byte element = magnitude[i];
if (element != 0) {
throw new NumberFormatException("signum-magnitude mismatch");
}
}
}
if (magnitude.length == 0) {
sign = 0;
numberLength = 1;
digits = new int[] { 0 };
} else {
sign = signum;
putBytesPositiveToIntegers(magnitude);
cutOffLeadingZeroes();
}
}
public BigInteger(byte[] val) {
if (val.length == 0) {
throw new NumberFormatException("Zero length BigInteger");
}
if (val[0] < 0) {
sign = -1;
putBytesNegativeToIntegers(val);
} else {
sign = 1;
putBytesPositiveToIntegers(val);
}
cutOffLeadingZeroes();
}
/* Package Constructors */
/**
* Constructs a number which array is of size 1.
*
* @param sign
* the sign of the number
* @param value
* the only one digit of array
*/
BigInteger(int sign, int value) {
this.sign = sign;
numberLength = 1;
digits = new int[] { value };
}
/**
* Constructs a number without to create new space. This construct should be
* used only if the three fields of representation are known.
*
* @param sign
* the sign of the number
* @param numberLength
* the length of the internal array
* @param digits
* a reference of some array created before
*/
BigInteger(int sign, int numberLength, int[] digits) {
this.sign = sign;
this.numberLength = numberLength;
this.digits = digits;
}
/**
* Creates a new {@code BigInteger} whose value is equal to the specified
* {@code long}.
*
* @param sign
* the sign of the number
* @param val
* the value of the new {@code BigInteger}.
*/
BigInteger(int sign, long val) {
// PRE: (val >= 0) && (sign >= -1) && (sign <= 1)
this.sign = sign;
if ((val & 0xFFFFFFFF00000000L) == 0) {
// It fits in one 'int'
numberLength = 1;
digits = new int[] { (int) val };
} else {
numberLength = 2;
digits = new int[] { (int) val, (int) (val >> 32) };
}
}
/**
* Creates a new {@code BigInteger} with the given sign and magnitude. This
* constructor does not create a copy, so any changes to the reference will
* affect the new number.
*
* @param signum
* The sign of the number represented by {@code digits}
* @param digits
* The magnitude of the number
*/
BigInteger(int signum, int digits[]) {
if (digits.length == 0) {
sign = 0;
numberLength = 1;
this.digits = new int[] { 0 };
} else {
sign = signum;
numberLength = digits.length;
this.digits = digits;
cutOffLeadingZeroes();
}
}
public static BigInteger valueOf(long val) {
if (val < 0) {
if (val != -1) {
return new BigInteger(-1, -val);
}
return MINUS_ONE;
} else if (val <= 10) {
return SMALL_VALUES[(int) val];
} else {// (val > 10)
return new BigInteger(1, val);
}
}
public byte[] toByteArray() {
if (this.sign == 0) {
return new byte[] { 0 };
}
BigInteger temp = this;
int bitLen = bitLength();
int iThis = getFirstNonzeroDigit();
int bytesLen = (bitLen >> 3) + 1;
/*
* Puts the little-endian int array representing the magnitude of this
* BigInteger into the big-endian byte array.
*/
byte[] bytes = new byte[bytesLen];
int firstByteNumber = 0;
int highBytes;
int digitIndex = 0;
int bytesInInteger = 4;
int digit;
int hB;
if (bytesLen - (numberLength << 2) == 1) {
bytes[0] = (byte) ((sign < 0) ? -1 : 0);
highBytes = 4;
firstByteNumber++;
} else {
hB = bytesLen & 3;
highBytes = (hB == 0) ? 4 : hB;
}
digitIndex = iThis;
bytesLen -= iThis << 2;
if (sign < 0) {
digit = -temp.digits[digitIndex];
digitIndex++;
if (digitIndex == numberLength) {
bytesInInteger = highBytes;
}
for (int i = 0; i < bytesInInteger; i++, digit >>= 8) {
bytes[--bytesLen] = (byte) digit;
}
while (bytesLen > firstByteNumber) {
digit = ~temp.digits[digitIndex];
digitIndex++;
if (digitIndex == numberLength) {
bytesInInteger = highBytes;
}
for (int i = 0; i < bytesInInteger; i++, digit >>= 8) {
bytes[--bytesLen] = (byte) digit;
}
}
} else {
while (bytesLen > firstByteNumber) {
digit = temp.digits[digitIndex];
digitIndex++;
if (digitIndex == numberLength) {
bytesInInteger = highBytes;
}
for (int i = 0; i < bytesInInteger; i++, digit >>= 8) {
bytes[--bytesLen] = (byte) digit;
}
}
}
return bytes;
}
/** @see BigInteger#BigInteger(String, int) */
private static void setFromString(BigInteger bi, String val, int radix) {
int sign;
int[] digits;
int numberLength;
int stringLength = val.length();
int startChar;
int endChar = stringLength;
if (val.charAt(0) == '-') {
sign = -1;
startChar = 1;
stringLength--;
} else {
sign = 1;
startChar = 0;
}
/*
* We use the following algorithm: split a string into portions of n
* characters and convert each portion to an integer according to the
* radix. Then convert an exp(radix, n) based number to binary using the
* multiplication method. See D. Knuth, The Art of Computer Programming,
* vol. 2.
*/
int charsPerInt = Conversion.digitFitInInt[radix];
int bigRadixDigitsLength = stringLength / charsPerInt;
int topChars = stringLength % charsPerInt;
if (topChars != 0) {
bigRadixDigitsLength++;
}
digits = new int[bigRadixDigitsLength];
// Get the maximal power of radix that fits in int
int bigRadix = Conversion.bigRadices[radix - 2];
// Parse an input string and accumulate the BigInteger's magnitude
int digitIndex = 0; // index of digits array
int substrEnd = startChar + ((topChars == 0) ? charsPerInt : topChars);
int newDigit;
for (int substrStart = startChar; substrStart < endChar; substrStart = substrEnd, substrEnd = substrStart
+ charsPerInt) {
int bigRadixDigit = Integer.parseInt(val.substring(substrStart,
substrEnd), radix);
newDigit = Multiplication.multiplyByInt(digits, digitIndex,
bigRadix);
newDigit += Elementary
.inplaceAdd(digits, digitIndex, bigRadixDigit);
digits[digitIndex++] = newDigit;
}
numberLength = digitIndex;
bi.sign = sign;
bi.numberLength = numberLength;
bi.digits = digits;
bi.cutOffLeadingZeroes();
}
public BigInteger abs() {
return ((sign < 0) ? new BigInteger(1, numberLength, digits) : this);
}
public BigInteger negate() {
return ((sign == 0) ? this
: new BigInteger(-sign, numberLength, digits));
}
public BigInteger add(BigInteger val) {
return Elementary.add(this, val);
}
public BigInteger subtract(BigInteger val) {
return Elementary.subtract(this, val);
}
public int signum() {
return sign;
}
public BigInteger shiftRight(int n) {
if ((n == 0) || (sign == 0)) {
return this;
}
return ((n > 0) ? BitLevel.shiftRight(this, n) : BitLevel.shiftLeft(
this, -n));
}
public BigInteger shiftLeft(int n) {
if ((n == 0) || (sign == 0)) {
return this;
}
return ((n > 0) ? BitLevel.shiftLeft(this, n) : BitLevel.shiftRight(
this, -n));
}
public int bitLength() {
return BitLevel.bitLength(this);
}
public boolean testBit(int n) {
if (n == 0) {
return ((digits[0] & 1) != 0);
}
if (n < 0) {
throw new ArithmeticException("Negative bit address");
}
int intCount = n >> 5;
if (intCount >= numberLength) {
return (sign < 0);
}
int digit = digits[intCount];
n = (1 << (n & 31)); // int with 1 set to the needed position
if (sign < 0) {
int firstNonZeroDigit = getFirstNonzeroDigit();
if (intCount < firstNonZeroDigit) {
return false;
} else if (firstNonZeroDigit == intCount) {
digit = -digit;
} else {
digit = ~digit;
}
}
return ((digit & n) != 0);
}
public BigInteger setBit(int n) {
if (!testBit(n)) {
return BitLevel.flipBit(this, n);
}
return this;
}
public BigInteger clearBit(int n) {
if (testBit(n)) {
return BitLevel.flipBit(this, n);
}
return this;
}
public BigInteger flipBit(int n) {
if (n < 0) {
throw new ArithmeticException("Negative bit address");
}
return BitLevel.flipBit(this, n);
}
public int getLowestSetBit() {
if (sign == 0) {
return -1;
}
// (sign != 0) implies that exists some non zero digit
int i = getFirstNonzeroDigit();
return ((i << 5) + Utils.numberOfTrailingZeros(digits[i]));
}
public int bitCount() {
return BitLevel.bitCount(this);
}
public BigInteger not() {
return Logical.not(this);
}
public BigInteger and(BigInteger val) {
return Logical.and(this, val);
}
public BigInteger or(BigInteger val) {
return Logical.or(this, val);
}
public BigInteger xor(BigInteger val) {
return Logical.xor(this, val);
}
public BigInteger andNot(BigInteger val) {
return Logical.andNot(this, val);
}
public int intValue() {
return (sign * digits[0]);
}
public long longValue() {
long value = (numberLength > 1) ? (((long) digits[1]) << 32)
| (digits[0] & 0xFFFFFFFFL) : (digits[0] & 0xFFFFFFFFL);
return (sign * value);
}
public float floatValue() {
return (float) doubleValue();
}
public double doubleValue() {
return Conversion.bigInteger2Double(this);
}
public int compareTo(Object o) throws ClassCastException {
BigInteger val = (BigInteger)o;
return compareTo(val);
}
public int compareTo(BigInteger val) {
if (sign > val.sign) {
return GREATER;
}
if (sign < val.sign) {
return LESS;
}
if (numberLength > val.numberLength) {
return sign;
}
if (numberLength < val.numberLength) {
return -val.sign;
}
// Equal sign and equal numberLength
return (sign * Elementary.compareArrays(digits, val.digits,
numberLength));
}
public BigInteger min(BigInteger val) {
return ((this.compareTo(val) == LESS) ? this : val);
}
public BigInteger max(BigInteger val) {
return ((this.compareTo(val) == GREATER) ? this : val);
}
public int hashCode() {
if (hashCode != 0) {
return hashCode;
}
for (int i = 0; i < digits.length; i++) {
hashCode = (hashCode * 33 + (digits[i] & 0xffffffff));
}
hashCode = hashCode * sign;
return hashCode;
}
public boolean equals(Object x) {
if (this == x) {
return true;
}
if (x instanceof BigInteger) {
BigInteger x1 = (BigInteger) x;
return sign == x1.sign && numberLength == x1.numberLength
&& equalsArrays(x1.digits);
}
return false;
}
boolean equalsArrays(final int[] b) {
int i;
for (i = numberLength - 1; (i >= 0) && (digits[i] == b[i]); i--) {
// Empty
}
return i < 0;
}
public String toString() {
return Conversion.toDecimalScaledString(this, 0);
}
public String toString(int radix) {
return Conversion.bigInteger2String(this, radix);
}
public BigInteger gcd(BigInteger val) {
BigInteger val1 = this.abs();
BigInteger val2 = val.abs();
// To avoid a possible division by zero
if (val1.signum() == 0) {
return val2;
} else if (val2.signum() == 0) {
return val1;
}
// Optimization for small operands
// (op2.bitLength() < 64) and (op1.bitLength() < 64)
if (((val1.numberLength == 1) || ((val1.numberLength == 2) && (val1.digits[1] > 0)))
&& (val2.numberLength == 1 || (val2.numberLength == 2 && val2.digits[1] > 0))) {
return BigInteger.valueOf(Division.gcdBinary(val1.longValue(), val2
.longValue()));
}
return Division.gcdBinary(val1.copy(), val2.copy());
}
public BigInteger multiply(BigInteger val) {
// This let us to throw NullPointerException when val == null
if (val.sign == 0) {
return ZERO;
}
if (sign == 0) {
return ZERO;
}
return Multiplication.multiply(this, val);
}
public BigInteger pow(int exp) {
if (exp < 0) {
throw new ArithmeticException("Negative exponent");
}
if (exp == 0) {
return ONE;
} else if (exp == 1 || equals(ONE) || equals(ZERO)) {
return this;
}
// if even take out 2^x factor which we can
// calculate by shifting.
if (!testBit(0)) {
int x = 1;
BigInteger factor = BigInteger.ONE.shiftLeft(exp);
while (!testBit(x)) {
factor = factor.shiftLeft(exp);
x++;
}
return factor.multiply(this.shiftRight(x).pow(exp));
}
return Multiplication.pow(this, exp);
}
public BigInteger[] divideAndRemainder(BigInteger divisor) {
int divisorSign = divisor.sign;
if (divisorSign == 0) {
throw new ArithmeticException("BigInteger divide by zero");
}
int divisorLen = divisor.numberLength;
int[] divisorDigits = divisor.digits;
if (divisorLen == 1) {
return Division.divideAndRemainderByInteger(this, divisorDigits[0],
divisorSign);
}
// res[0] is a quotient and res[1] is a remainder:
int[] thisDigits = digits;
int thisLen = numberLength;
int cmp = (thisLen != divisorLen) ? ((thisLen > divisorLen) ? 1 : -1)
: Elementary.compareArrays(thisDigits, divisorDigits, thisLen);
if (cmp < 0) {
return new BigInteger[] { ZERO, this };
}
int thisSign = sign;
int quotientLength = thisLen - divisorLen + 1;
int remainderLength = divisorLen;
int quotientSign = ((thisSign == divisorSign) ? 1 : -1);
int quotientDigits[] = new int[quotientLength];
int remainderDigits[] = Division.divide(quotientDigits, quotientLength,
thisDigits, thisLen, divisorDigits, divisorLen);
BigInteger result0 = new BigInteger(quotientSign, quotientLength,
quotientDigits);
BigInteger result1 = new BigInteger(thisSign, remainderLength,
remainderDigits);
result0.cutOffLeadingZeroes();
result1.cutOffLeadingZeroes();
return new BigInteger[] { result0, result1 };
}
public BigInteger divide(BigInteger divisor) {
if (divisor.sign == 0) {
throw new ArithmeticException("BigInteger divide by zero");
}
int divisorSign = divisor.sign;
if (divisor.isOne()) {
return ((divisor.sign > 0) ? this : this.negate());
}
int thisSign = sign;
int thisLen = numberLength;
int divisorLen = divisor.numberLength;
if (thisLen + divisorLen == 2) {
long val = (digits[0] & 0xFFFFFFFFL)
/ (divisor.digits[0] & 0xFFFFFFFFL);
if (thisSign != divisorSign) {
val = -val;
}
return valueOf(val);
}
int cmp = ((thisLen != divisorLen) ? ((thisLen > divisorLen) ? 1 : -1)
: Elementary.compareArrays(digits, divisor.digits, thisLen));
if (cmp == EQUALS) {
return ((thisSign == divisorSign) ? ONE : MINUS_ONE);
}
if (cmp == LESS) {
return ZERO;
}
int resLength = thisLen - divisorLen + 1;
int resDigits[] = new int[resLength];
int resSign = ((thisSign == divisorSign) ? 1 : -1);
if (divisorLen == 1) {
Division.divideArrayByInt(resDigits, digits, thisLen,
divisor.digits[0]);
} else {
Division.divide(resDigits, resLength, digits, thisLen,
divisor.digits, divisorLen);
}
BigInteger result = new BigInteger(resSign, resLength, resDigits);
result.cutOffLeadingZeroes();
return result;
}
public BigInteger remainder(BigInteger divisor) {
if (divisor.sign == 0) {
throw new ArithmeticException("BigInteger divide by zero");
}
int thisLen = numberLength;
int divisorLen = divisor.numberLength;
if (((thisLen != divisorLen) ? ((thisLen > divisorLen) ? 1 : -1)
: Elementary.compareArrays(digits, divisor.digits, thisLen)) == LESS) {
return this;
}
int resLength = divisorLen;
int resDigits[] = new int[resLength];
if (resLength == 1) {
resDigits[0] = Division.remainderArrayByInt(digits, thisLen,
divisor.digits[0]);
} else {
int qLen = thisLen - divisorLen + 1;
resDigits = Division.divide(null, qLen, digits, thisLen,
divisor.digits, divisorLen);
}
BigInteger result = new BigInteger(sign, resLength, resDigits);
result.cutOffLeadingZeroes();
return result;
}
public BigInteger modInverse(BigInteger m) {
if (m.sign <= 0) {
throw new ArithmeticException("BigInteger: modulus not positive");
}
// If both are even, no inverse exists
if (!(testBit(0) || m.testBit(0))) {
throw new ArithmeticException("BigInteger not invertible");
}
if (m.isOne()) {
return ZERO;
}
// From now on: (m > 1)
BigInteger res = Division.modInverseMontgomery(abs().mod(m), m);
if (res.sign == 0) {
throw new ArithmeticException("BigInteger not invertible");
}
res = ((sign < 0) ? m.subtract(res) : res);
return res;
}
public BigInteger modPow(BigInteger exponent, BigInteger m) {
if (m.sign <= 0) {
throw new ArithmeticException("BigInteger: modulus not positive");
}
BigInteger base = this;
if (m.isOne() | (exponent.sign > 0 & base.sign == 0)) {
return BigInteger.ZERO;
}
if (base.sign == 0 && exponent.sign == 0) {
return BigInteger.ONE;
}
if (exponent.sign < 0) {
base = modInverse(m);
exponent = exponent.negate();
}
// From now on: (m > 0) and (exponent >= 0)
BigInteger res = (m.testBit(0)) ? Division.oddModPow(base.abs(),
exponent, m) : Division.evenModPow(base.abs(), exponent, m);
if ((base.sign < 0) && exponent.testBit(0)) {
// -b^e mod m == ((-1 mod m) * (b^e mod m)) mod m
res = m.subtract(BigInteger.ONE).multiply(res).mod(m);
}
// else exponent is even, so base^exp is positive
return res;
}
public BigInteger mod(BigInteger m) {
if (m.sign <= 0) {
throw new ArithmeticException("BigInteger: modulus not positive");
}
BigInteger rem = remainder(m);
return ((rem.sign < 0) ? rem.add(m) : rem);
}
public boolean isProbablePrime(int certainty) {
return Primality.isProbablePrime(abs(), certainty);
}
/* [CG 20080209] New in 1.5
public BigInteger nextProbablePrime() {
if (sign < 0) {
throw new ArithmeticException("start < 0: " + this);
}
return Primality.nextProbablePrime(this);
}
*/
public static BigInteger probablePrime(int bitLength, Random rnd) {
return new BigInteger(bitLength, 100, rnd);
}
/* Private Methods */
/** Decreases {@code numberLength} if there are zero high elements. */
final void cutOffLeadingZeroes() {
while ((numberLength > 0) && (digits[--numberLength] == 0)) {
// Empty
}
if (digits[numberLength++] == 0) {
sign = 0;
}
}
/** Tests if {@code this.abs()} is equals to {@code ONE} */
boolean isOne() {
return ((numberLength == 1) && (digits[0] == 1));
}
/**
* Puts a big-endian byte array into a little-endian int array.
*/
private void putBytesPositiveToIntegers(byte[] byteValues) {
int bytesLen = byteValues.length;
int highBytes = bytesLen & 3;
numberLength = (bytesLen >> 2) + ((highBytes == 0) ? 0 : 1);
digits = new int[numberLength];
int i = 0;
// Put bytes to the int array starting from the end of the byte array
while (bytesLen > highBytes) {
digits[i++] = (byteValues[--bytesLen] & 0xFF)
| (byteValues[--bytesLen] & 0xFF) << 8
| (byteValues[--bytesLen] & 0xFF) << 16
| (byteValues[--bytesLen] & 0xFF) << 24;
}
// Put the first bytes in the highest element of the int array
for (int j = 0; j < bytesLen; j++) {
digits[i] = (digits[i] << 8) | (byteValues[j] & 0xFF);
}
}
/**
* Puts a big-endian byte array into a little-endian applying two
* complement.
*/
private void putBytesNegativeToIntegers(byte[] byteValues) {
int bytesLen = byteValues.length;
int highBytes = bytesLen & 3;
numberLength = (bytesLen >> 2) + ((highBytes == 0) ? 0 : 1);
digits = new int[numberLength];
int i = 0;
// Setting the sign
digits[numberLength - 1] = -1;
// Put bytes to the int array starting from the end of the byte array
while (bytesLen > highBytes) {
digits[i] = (byteValues[--bytesLen] & 0xFF)
| (byteValues[--bytesLen] & 0xFF) << 8
| (byteValues[--bytesLen] & 0xFF) << 16
| (byteValues[--bytesLen] & 0xFF) << 24;
if (digits[i] != 0) {
digits[i] = -digits[i];
firstNonzeroDigit = i;
i++;
while (bytesLen > highBytes) {
digits[i] = (byteValues[--bytesLen] & 0xFF)
| (byteValues[--bytesLen] & 0xFF) << 8
| (byteValues[--bytesLen] & 0xFF) << 16
| (byteValues[--bytesLen] & 0xFF) << 24;
digits[i] = ~digits[i];
i++;
}
break;
}
i++;
}
if (highBytes != 0) {
// Put the first bytes in the highest element of the int array
if (firstNonzeroDigit != -2) {
for (int j = 0; j < bytesLen; j++) {
digits[i] = (digits[i] << 8) | (byteValues[j] & 0xFF);
}
digits[i] = ~digits[i];
} else {
for (int j = 0; j < bytesLen; j++) {
digits[i] = (digits[i] << 8) | (byteValues[j] & 0xFF);
}
digits[i] = -digits[i];
}
}
}
int getFirstNonzeroDigit() {
if (firstNonzeroDigit == -2) {
int i;
if (this.sign == 0) {
i = -1;
} else {
for (i = 0; digits[i] == 0; i++) {
// Empty
}
}
firstNonzeroDigit = i;
}
return firstNonzeroDigit;
}
/*
* Returns a copy of the current instance to achieve immutability
*/
BigInteger copy() {
int[] copyDigits = new int[numberLength];
System.arraycopy(digits, 0, copyDigits, 0, numberLength);
return new BigInteger(sign, numberLength, copyDigits);
}
private void readObject(ObjectInputStream in) throws IOException,
ClassNotFoundException {
in.defaultReadObject();
sign = signum;
putBytesPositiveToIntegers(magnitude);
cutOffLeadingZeroes();
}
private void writeObject(ObjectOutputStream out) throws IOException {
signum = signum();
magnitude = abs().toByteArray();
out.defaultWriteObject();
}
void unCache() {
firstNonzeroDigit = -2;
}
}