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tbuktu/BigIntegerTest.java

Created January 10, 2012 04:38
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Updated BigInteger unit test for https://gist.github.com/1576025
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BigIntegerTest.java
/*
* Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 4181191 4161971 4227146 4194389 4823171 4624738 4812225
* @summary tests methods in BigInteger
* @run main/timeout=400 BigIntegerTest
* @author madbot
*/
import java.util.Random;
import java.math.BigInteger;
import java.io.*;
/**
* This is a simple test class created to ensure that the results
* generated by BigInteger adhere to certain identities. Passing
* this test is a strong assurance that the BigInteger operations
* are working correctly.
*
* Three arguments may be specified which give the number of
* decimal digits you desire in the three batches of test numbers.
*
* The tests are performed on arrays of random numbers which are
* generated by a Random class as well as special cases which
* throw in boundary numbers such as 0, 1, maximum sized, etc.
*
*/
public class BigIntegerTest {
static Random rnd = new Random();
static int size = 1000; // numbers per batch
static boolean failure = false;
public static void pow(int order) {
int failCount1 = 0;
for (int i=0; i<size; i++) {
int power = rnd.nextInt(6) +2;
BigInteger x = fetchNumber(order);
BigInteger y = x.pow(power);
BigInteger z = x;
for (int j=1; j<power; j++)
z = z.multiply(x);
if (!y.equals(z))
failCount1++;
}
report("pow", failCount1);
}
public static void arithmetic(int order) {
int failCount = 0;
for (int i=0; i<size; i++) {
BigInteger x = fetchNumber(order);
while(x.compareTo(BigInteger.ZERO) != 1)
x = fetchNumber(order);
BigInteger y = fetchNumber(order/2);
while(x.compareTo(y) == -1)
y = fetchNumber(order/2);
if (y.equals(BigInteger.ZERO))
y = y.add(BigInteger.ONE);
BigInteger baz = x.divide(y);
baz = baz.multiply(y);
baz = baz.add(x.remainder(y));
baz = baz.subtract(x);
if (!baz.equals(BigInteger.ZERO))
failCount++;
}
report("Arithmetic I for " + order + " bits", failCount);
failCount = 0;
for (int i=0; i<100; i++) {
BigInteger x = fetchNumber(order);
while(x.compareTo(BigInteger.ZERO) != 1)
x = fetchNumber(order);
BigInteger y = fetchNumber(order/2);
while(x.compareTo(y) == -1)
y = fetchNumber(order/2);
if (y.equals(BigInteger.ZERO))
y = y.add(BigInteger.ONE);
BigInteger baz[] = x.divideAndRemainder(y);
baz[0] = baz[0].multiply(y);
baz[0] = baz[0].add(baz[1]);
baz[0] = baz[0].subtract(x);
if (!baz[0].equals(BigInteger.ZERO))
failCount++;
}
report("Arithmetic II for " + order + " bits", failCount);
}
public static void bitCount() {
int failCount = 0;
for (int i=0; i<size*10; i++) {
int x = rnd.nextInt();
BigInteger bigX = BigInteger.valueOf((long)x);
int bit = (x < 0 ? 0 : 1);
int tmp = x, bitCount = 0;
for (int j=0; j<32; j++) {
bitCount += ((tmp & 1) == bit ? 1 : 0);
tmp >>= 1;
}
if (bigX.bitCount() != bitCount) {
//System.err.println(x+": "+bitCount+", "+bigX.bitCount());
failCount++;
}
}
report("Bit Count", failCount);
}
public static void bitLength() {
int failCount = 0;
for (int i=0; i<size*10; i++) {
int x = rnd.nextInt();
BigInteger bigX = BigInteger.valueOf((long)x);
int signBit = (x < 0 ? 0x80000000 : 0);
int tmp = x, bitLength, j;
for (j=0; j<32 && (tmp & 0x80000000)==signBit; j++)
tmp <<= 1;
bitLength = 32 - j;
if (bigX.bitLength() != bitLength) {
//System.err.println(x+": "+bitLength+", "+bigX.bitLength());
failCount++;
}
}
report("BitLength", failCount);
}
public static void bitOps(int order) {
int failCount1 = 0, failCount2 = 0, failCount3 = 0;
for (int i=0; i<size*5; i++) {
BigInteger x = fetchNumber(order);
BigInteger y;
/* Test setBit and clearBit (and testBit) */
if (x.signum() < 0) {
y = BigInteger.valueOf(-1);
for (int j=0; j<x.bitLength(); j++)
if (!x.testBit(j))
y = y.clearBit(j);
} else {
y = BigInteger.ZERO;
for (int j=0; j<x.bitLength(); j++)
if (x.testBit(j))
y = y.setBit(j);
}
if (!x.equals(y))
failCount1++;
/* Test flipBit (and testBit) */
y = BigInteger.valueOf(x.signum()<0 ? -1 : 0);
for (int j=0; j<x.bitLength(); j++)
if (x.signum()<0 ^ x.testBit(j))
y = y.flipBit(j);
if (!x.equals(y))
failCount2++;
}
report("clearBit/testBit", failCount1);
report("flipBit/testBit", failCount2);
for (int i=0; i<size*5; i++) {
BigInteger x = fetchNumber(order);
/* Test getLowestSetBit() */
int k = x.getLowestSetBit();
if (x.signum() == 0) {
if (k != -1)
failCount3++;
} else {
BigInteger z = x.and(x.negate());
int j;
for (j=0; j<z.bitLength() && !z.testBit(j); j++)
;
if (k != j)
failCount3++;
}
}
report("getLowestSetBit", failCount3);
}
public static void bitwise(int order) {
/* Test identity x^y == x|y &~ x&y */
int failCount = 0;
for (int i=0; i<size; i++) {
BigInteger x = fetchNumber(order);
BigInteger y = fetchNumber(order);
BigInteger z = x.xor(y);
BigInteger w = x.or(y).andNot(x.and(y));
if (!z.equals(w))
failCount++;
}
report("Logic (^ | & ~)", failCount);
/* Test identity x &~ y == ~(~x | y) */
failCount = 0;
for (int i=0; i<size; i++) {
BigInteger x = fetchNumber(order);
BigInteger y = fetchNumber(order);
BigInteger z = x.andNot(y);
BigInteger w = x.not().or(y).not();
if (!z.equals(w))
failCount++;
}
report("Logic (&~ | ~)", failCount);
}
public static void shift(int order) {
int failCount1 = 0;
int failCount2 = 0;
int failCount3 = 0;
for (int i=0; i<100; i++) {
BigInteger x = fetchNumber(order);
int n = Math.abs(rnd.nextInt()%200);
if (!x.shiftLeft(n).equals
(x.multiply(BigInteger.valueOf(2L).pow(n))))
failCount1++;
BigInteger y[] =x.divideAndRemainder(BigInteger.valueOf(2L).pow(n));
BigInteger z = (x.signum()<0 && y[1].signum()!=0
? y[0].subtract(BigInteger.ONE)
: y[0]);
BigInteger b = x.shiftRight(n);
if (!b.equals(z)) {
System.err.println("Input is "+x.toString(2));
System.err.println("shift is "+n);
System.err.println("Divided "+z.toString(2));
System.err.println("Shifted is "+b.toString(2));
if (b.toString().equals(z.toString()))
System.err.println("Houston, we have a problem.");
failCount2++;
}
if (!x.shiftLeft(n).shiftRight(n).equals(x))
failCount3++;
}
report("baz shiftLeft", failCount1);
report("baz shiftRight", failCount2);
report("baz shiftLeft/Right", failCount3);
}
public static void divideAndRemainder(int order) {
int failCount1 = 0;
for (int i=0; i<size; i++) {
BigInteger x = fetchNumber(order).abs();
while(x.compareTo(BigInteger.valueOf(3L)) != 1)
x = fetchNumber(order).abs();
BigInteger z = x.divide(BigInteger.valueOf(2L));
BigInteger y[] = x.divideAndRemainder(x);
if (!y[0].equals(BigInteger.ONE)) {
failCount1++;
System.err.println("fail1 x :"+x);
System.err.println(" y :"+y);
}
else if (!y[1].equals(BigInteger.ZERO)) {
failCount1++;
System.err.println("fail2 x :"+x);
System.err.println(" y :"+y);
}
y = x.divideAndRemainder(z);
if (!y[0].equals(BigInteger.valueOf(2))) {
failCount1++;
System.err.println("fail3 x :"+x);
System.err.println(" y :"+y);
}
}
report("divideAndRemainder for " + order + " bits", failCount1);
}
public static void stringConv() {
int failCount = 0;
for (int i=0; i<100; i++) {
byte xBytes[] = new byte[Math.abs(rnd.nextInt())%100+1];
rnd.nextBytes(xBytes);
BigInteger x = new BigInteger(xBytes);
for (int radix=2; radix < 37; radix++) {
String result = x.toString(radix);
BigInteger test = new BigInteger(result, radix);
if (!test.equals(x)) {
failCount++;
System.err.println("BigInteger toString: "+x);
System.err.println("Test: "+test);
System.err.println(radix);
}
}
}
report("String Conversion", failCount);
}
public static void byteArrayConv(int order) {
int failCount = 0;
for (int i=0; i<size; i++) {
BigInteger x = fetchNumber(order);
while (x.equals(BigInteger.ZERO))
x = fetchNumber(order);
BigInteger y = new BigInteger(x.toByteArray());
if (!x.equals(y)) {
failCount++;
System.err.println("orig is "+x);
System.err.println("new is "+y);
}
}
report("Array Conversion", failCount);
}
public static void modInv(int order) {
int failCount = 0, successCount = 0, nonInvCount = 0;
for (int i=0; i<size; i++) {
BigInteger x = fetchNumber(order);
while(x.equals(BigInteger.ZERO))
x = fetchNumber(order);
BigInteger m = fetchNumber(order).abs();
while(m.compareTo(BigInteger.ONE) != 1)
m = fetchNumber(order).abs();
try {
BigInteger inv = x.modInverse(m);
BigInteger prod = inv.multiply(x).remainder(m);
if (prod.signum() == -1)
prod = prod.add(m);
if (prod.equals(BigInteger.ONE))
successCount++;
else
failCount++;
} catch(ArithmeticException e) {
nonInvCount++;
}
}
report("Modular Inverse for " + order + " bits", failCount);
}
public static void modExp(int order1, int order2) {
int failCount = 0;
for (int i=0; i<size/10; i++) {
BigInteger m = fetchNumber(order1).abs();
while(m.compareTo(BigInteger.ONE) != 1)
m = fetchNumber(order1).abs();
BigInteger base = fetchNumber(order2);
BigInteger exp = fetchNumber(8).abs();
BigInteger z = base.modPow(exp, m);
BigInteger w = base.pow(exp.intValue()).mod(m);
if (!z.equals(w)) {
System.err.println("z is "+z);
System.err.println("w is "+w);
System.err.println("mod is "+m);
System.err.println("base is "+base);
System.err.println("exp is "+exp);
failCount++;
}
}
report("Exponentiation I", failCount);
}
// This test is based on Fermat's theorem
// which is not ideal because base must not be multiple of modulus
// and modulus must be a prime or pseudoprime (Carmichael number)
public static void modExp2(int order) {
int failCount = 0;
for (int i=0; i<10; i++) {
BigInteger m = new BigInteger(100, 5, rnd);
while(m.compareTo(BigInteger.ONE) != 1)
m = new BigInteger(100, 5, rnd);
BigInteger exp = m.subtract(BigInteger.ONE);
BigInteger base = fetchNumber(order).abs();
while(base.compareTo(m) != -1)
base = fetchNumber(order).abs();
while(base.equals(BigInteger.ZERO))
base = fetchNumber(order).abs();
BigInteger one = base.modPow(exp, m);
if (!one.equals(BigInteger.ONE)) {
System.err.println("m is "+m);
System.err.println("base is "+base);
System.err.println("exp is "+exp);
failCount++;
}
}
report("Exponentiation II", failCount);
}
private static final int[] mersenne_powers = {
521, 607, 1279, 2203, 2281, 3217, 4253, 4423, 9689, 9941, 11213, 19937,
21701, 23209, 44497, 86243, 110503, 132049, 216091, 756839, 859433,
1257787, 1398269, 2976221, 3021377, 6972593, 13466917 };
private static final long[] carmichaels = {
561,1105,1729,2465,2821,6601,8911,10585,15841,29341,41041,46657,52633,
62745,63973,75361,101101,115921,126217,162401,172081,188461,252601,
278545,294409,314821,334153,340561,399001,410041,449065,488881,512461,
225593397919L };
// Note: testing the larger ones takes too long.
private static final int NUM_MERSENNES_TO_TEST = 7;
// Note: this constant used for computed Carmichaels, not the array above
private static final int NUM_CARMICHAELS_TO_TEST = 5;
private static final String[] customer_primes = {
"120000000000000000000000000000000019",
"633825300114114700748351603131",
"1461501637330902918203684832716283019651637554291",
"779626057591079617852292862756047675913380626199",
"857591696176672809403750477631580323575362410491",
"910409242326391377348778281801166102059139832131",
"929857869954035706722619989283358182285540127919",
"961301750640481375785983980066592002055764391999",
"1267617700951005189537696547196156120148404630231",
"1326015641149969955786344600146607663033642528339" };
private static final BigInteger ZERO = BigInteger.ZERO;
private static final BigInteger ONE = BigInteger.ONE;
private static final BigInteger TWO = new BigInteger("2");
private static final BigInteger SIX = new BigInteger("6");
private static final BigInteger TWELVE = new BigInteger("12");
private static final BigInteger EIGHTEEN = new BigInteger("18");
public static void prime() {
BigInteger p1, p2, c1;
int failCount = 0;
// Test consistency
for(int i=0; i<10; i++) {
p1 = BigInteger.probablePrime(100, rnd);
if (!p1.isProbablePrime(100)) {
System.err.println("Consistency "+p1.toString(16));
failCount++;
}
}
// Test some known Mersenne primes (2^n)-1
// The array holds the exponents, not the numbers being tested
for (int i=0; i<NUM_MERSENNES_TO_TEST; i++) {
p1 = new BigInteger("2");
p1 = p1.pow(mersenne_powers[i]);
p1 = p1.subtract(BigInteger.ONE);
if (!p1.isProbablePrime(100)) {
System.err.println("Mersenne prime "+i+ " failed.");
failCount++;
}
}
// Test some primes reported by customers as failing in the past
for (int i=0; i<customer_primes.length; i++) {
p1 = new BigInteger(customer_primes[i]);
if (!p1.isProbablePrime(100)) {
System.err.println("Customer prime "+i+ " failed.");
failCount++;
}
}
// Test some known Carmichael numbers.
for (int i=0; i<carmichaels.length; i++) {
c1 = BigInteger.valueOf(carmichaels[i]);
if(c1.isProbablePrime(100)) {
System.err.println("Carmichael "+i+ " reported as prime.");
failCount++;
}
}
// Test some computed Carmichael numbers.
// Numbers of the form (6k+1)(12k+1)(18k+1) are Carmichael numbers if
// each of the factors is prime
int found = 0;
BigInteger f1 = new BigInteger(40, 100, rnd);
while (found < NUM_CARMICHAELS_TO_TEST) {
BigInteger k = null;
BigInteger f2, f3;
f1 = f1.nextProbablePrime();
BigInteger[] result = f1.subtract(ONE).divideAndRemainder(SIX);
if (result[1].equals(ZERO)) {
k = result[0];
f2 = k.multiply(TWELVE).add(ONE);
if (f2.isProbablePrime(100)) {
f3 = k.multiply(EIGHTEEN).add(ONE);
if (f3.isProbablePrime(100)) {
c1 = f1.multiply(f2).multiply(f3);
if (c1.isProbablePrime(100)) {
System.err.println("Computed Carmichael "
+c1.toString(16));
failCount++;
}
found++;
}
}
}
f1 = f1.add(TWO);
}
// Test some composites that are products of 2 primes
for (int i=0; i<50; i++) {
p1 = BigInteger.probablePrime(100, rnd);
p2 = BigInteger.probablePrime(100, rnd);
c1 = p1.multiply(p2);
if (c1.isProbablePrime(100)) {
System.err.println("Composite failed "+c1.toString(16));
failCount++;
}
}
for (int i=0; i<4; i++) {
p1 = BigInteger.probablePrime(600, rnd);
p2 = BigInteger.probablePrime(600, rnd);
c1 = p1.multiply(p2);
if (c1.isProbablePrime(100)) {
System.err.println("Composite failed "+c1.toString(16));
failCount++;
}
}
report("Prime", failCount);
}
private static final long[] primesTo100 = {
2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97
};
private static final long[] aPrimeSequence = {
1999999003L, 1999999013L, 1999999049L, 1999999061L, 1999999081L,
1999999087L, 1999999093L, 1999999097L, 1999999117L, 1999999121L,
1999999151L, 1999999171L, 1999999207L, 1999999219L, 1999999271L,
1999999321L, 1999999373L, 1999999423L, 1999999439L, 1999999499L,
1999999553L, 1999999559L, 1999999571L, 1999999609L, 1999999613L,
1999999621L, 1999999643L, 1999999649L, 1999999657L, 1999999747L,
1999999763L, 1999999777L, 1999999811L, 1999999817L, 1999999829L,
1999999853L, 1999999861L, 1999999871L, 1999999873
};
public static void nextProbablePrime() throws Exception {
int failCount = 0;
BigInteger p1, p2, p3;
p1 = p2 = p3 = ZERO;
// First test nextProbablePrime on the low range starting at zero
for (int i=0; i<primesTo100.length; i++) {
p1 = p1.nextProbablePrime();
if (p1.longValue() != primesTo100[i]) {
System.err.println("low range primes failed");
System.err.println("p1 is "+p1);
System.err.println("expected "+primesTo100[i]);
failCount++;
}
}
// Test nextProbablePrime on a relatively small, known prime sequence
p1 = BigInteger.valueOf(aPrimeSequence[0]);
for (int i=1; i<aPrimeSequence.length; i++) {
p1 = p1.nextProbablePrime();
if (p1.longValue() != aPrimeSequence[i]) {
System.err.println("prime sequence failed");
failCount++;
}
}
// Next, pick some large primes, use nextProbablePrime to find the
// next one, and make sure there are no primes in between
for (int i=0; i<100; i+=10) {
p1 = BigInteger.probablePrime(50 + i, rnd);
p2 = p1.add(ONE);
p3 = p1.nextProbablePrime();
while(p2.compareTo(p3) < 0) {
if (p2.isProbablePrime(100)){
System.err.println("nextProbablePrime failed");
System.err.println("along range "+p1.toString(16));
System.err.println("to "+p3.toString(16));
failCount++;
break;
}
p2 = p2.add(ONE);
}
}
report("nextProbablePrime", failCount);
}
public static void serialize() throws Exception {
int failCount = 0;
String bitPatterns[] = {
"ffffffff00000000ffffffff00000000ffffffff00000000",
"ffffffffffffffffffffffff000000000000000000000000",
"ffffffff0000000000000000000000000000000000000000",
"10000000ffffffffffffffffffffffffffffffffffffffff",
"100000000000000000000000000000000000000000000000",
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
"-ffffffff00000000ffffffff00000000ffffffff00000000",
"-ffffffffffffffffffffffff000000000000000000000000",
"-ffffffff0000000000000000000000000000000000000000",
"-10000000ffffffffffffffffffffffffffffffffffffffff",
"-100000000000000000000000000000000000000000000000",
"-aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
};
for(int i = 0; i < bitPatterns.length; i++) {
BigInteger b1 = new BigInteger(bitPatterns[i], 16);
BigInteger b2 = null;
File f = new File("serialtest");
try (FileOutputStream fos = new FileOutputStream(f)) {
try (ObjectOutputStream oos = new ObjectOutputStream(fos)) {
oos.writeObject(b1);
oos.flush();
}
try (FileInputStream fis = new FileInputStream(f);
ObjectInputStream ois = new ObjectInputStream(fis))
{
b2 = (BigInteger)ois.readObject();
}
if (!b1.equals(b2) ||
!b1.equals(b1.or(b2))) {
failCount++;
System.err.println("Serialized failed for hex " +
b1.toString(16));
}
}
f.delete();
}
for(int i=0; i<10; i++) {
BigInteger b1 = fetchNumber(rnd.nextInt(100));
BigInteger b2 = null;
File f = new File("serialtest");
try (FileOutputStream fos = new FileOutputStream(f)) {
try (ObjectOutputStream oos = new ObjectOutputStream(fos)) {
oos.writeObject(b1);
oos.flush();
}
try (FileInputStream fis = new FileInputStream(f);
ObjectInputStream ois = new ObjectInputStream(fis))
{
b2 = (BigInteger)ois.readObject();
}
}
if (!b1.equals(b2) ||
!b1.equals(b1.or(b2)))
failCount++;
f.delete();
}
report("Serialize", failCount);
}
/**
* Main to interpret arguments and run several tests.
*
* Up to three arguments may be given to specify the size of BigIntegers
* used for call parameters 1, 2, and 3. The size is interpreted as
* the maximum number of decimal digits that the parameters will have.
*
*/
public static void main(String[] args) throws Exception {
// Some variables for sizing test numbers in bits
int order1 = 100;
int order2 = 60;
int order3 = 1800; // #bits for testing Karatsuba and Burnikel-Ziegler
int order4 = 3000; // #bits for testing Toom-Cook
if (args.length >0)
order1 = (int)((Integer.parseInt(args[0]))* 3.333);
if (args.length >1)
order2 = (int)((Integer.parseInt(args[1]))* 3.333);
if (args.length >2)
order3 = (int)((Integer.parseInt(args[2]))* 3.333);
if (args.length >3)
order4 = (int)((Integer.parseInt(args[3]))* 3.333);
prime();
nextProbablePrime();
arithmetic(order1); // small numbers
arithmetic(order3); // Karatsuba / Burnikel-Ziegler range
arithmetic(order4); // Toom-Cook range
divideAndRemainder(order1); // small numbers
divideAndRemainder(order3); // Karatsuba / Burnikel-Ziegler range
divideAndRemainder(order4); // Toom-Cook range
pow(order1);
bitCount();
bitLength();
bitOps(order1);
bitwise(order1);
shift(order1);
byteArrayConv(order1);
modInv(order1); // small numbers
modInv(order3); // Karatsuba / Burnikel-Ziegler range
modInv(order4); // Toom-Cook range
modExp(order1, order2);
modExp2(order1);
stringConv();
serialize();
if (failure)
throw new RuntimeException("Failure in BigIntegerTest.");
}
/*
* Get a random or boundary-case number. This is designed to provide
* a lot of numbers that will find failure points, such as max sized
* numbers, empty BigIntegers, etc.
*
* If order is less than 2, order is changed to 2.
*/
private static BigInteger fetchNumber(int order) {
boolean negative = rnd.nextBoolean();
int numType = rnd.nextInt(7);
BigInteger result = null;
if (order < 2) order = 2;
switch (numType) {
case 0: // Empty
result = BigInteger.ZERO;
break;
case 1: // One
result = BigInteger.ONE;
break;
case 2: // All bits set in number
int numBytes = (order+7)/8;
byte[] fullBits = new byte[numBytes];
for(int i=0; i<numBytes; i++)
fullBits[i] = (byte)0xff;
int excessBits = 8*numBytes - order;
fullBits[0] &= (1 << (8-excessBits)) - 1;
result = new BigInteger(1, fullBits);
break;
case 3: // One bit in number
result = BigInteger.ONE.shiftLeft(rnd.nextInt(order));
break;
case 4: // Random bit density
int iterations = rnd.nextInt(order-1);
result = BigInteger.ONE.shiftLeft(rnd.nextInt(order));
for(int i=0; i<iterations; i++) {
BigInteger temp = BigInteger.ONE.shiftLeft(
rnd.nextInt(order));
result = result.or(temp);
}
break;
case 5: // Runs of consecutive ones and zeros
result = ZERO;
int remaining = order;
int bit = rnd.nextInt(2);
while (remaining > 0) {
int runLength = Math.min(remaining, rnd.nextInt(order));
result = result.shiftLeft(runLength);
if (bit > 0)
result = result.add(ONE.shiftLeft(runLength).subtract(ONE));
remaining -= runLength;
bit = 1 - bit;
}
break;
default: // random bits
result = new BigInteger(order, rnd);
}
if (negative)
result = result.negate();
return result;
}
static void report(String testName, int failCount) {
System.err.println(testName+": " +
(failCount==0 ? "Passed":"Failed("+failCount+")"));
if (failCount > 0)
failure = true;
}
}
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