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* 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.
*/
package org.apache.commons.math4.primes;
import java.util.HashSet;
import java.util.List;
import org.apache.commons.math4.exception.MathIllegalArgumentException;
import org.apache.commons.math4.exception.util.LocalizedFormats;
import org.apache.commons.math4.primes.Primes;
import org.apache.commons.math4.primes.SmallPrimes;
import org.junit.Assert;
import org.junit.Test;
public class PrimesTest {
public static final int[] PRIMES = {//primes here have been verified one by one using Dario Alejandro Alpern's tool, see http://www.alpertron.com.ar/ECM.HTM
2,3,5,7,11,13,17,19,23,29,31,43,47,53,71,73,79,89,97,
107,137,151,157,271,293,331,409,607,617,683,829,
1049,1103,1229,1657,
2039,2053,//around first boundary in miller-rabin
2251,2389,2473,2699,3271,3389,3449,5653,6449,6869,9067,9091,
11251,12433,12959,22961,41047,46337,65413,80803,91577,92693,
118423,656519,795659,
1373639,1373677,//around second boundary in miller-rabin
588977,952381,
1013041,1205999,2814001,
22605091,
25325981,25326023,//around third boundary in miller-rabin
100000007,715827881,
2147483647//Integer.MAX_VALUE
};
public static final int[] NOT_PRIMES = {//composite chosen at random + particular values used in algorithms such as boundaries for millerRabin
4,6,8,9,10,12,14,15,16,18,20,21,22,24,25,
275,
2037,2041,2045,2046,2047,2048,2049,2051,2055,//around first boundary in miller-rabin
9095,
463465,
1373637,1373641,1373651,1373652,1373653,1373654,1373655,1373673,1373675,1373679,//around second boundary in miller-rabin
25325979,25325983,25325993,25325997,25325999,25326001,25326003,25326007,25326009,25326011,25326021,25326025,//around third boundary in miller-rabin
100000005,
1073741341,1073741823,2147473649,2147483641,2147483643,2147483645,2147483646};
public static final int[] BELOW_2 = {
Integer.MIN_VALUE,-1,0,1};
void assertPrimeFactorsException(int n, Throwable expected) {
try {
Primes.primeFactors(n);
Assert.fail("Exception not thrown");
} catch (Throwable e) {
Assert.assertEquals(expected.getClass(), e.getClass());
if (expected.getMessage() != null) {
Assert.assertEquals(expected.getMessage(), e.getMessage());
}
}
}
void assertNextPrimeException(int n, Throwable expected){
try {
Primes.nextPrime(n);
Assert.fail("Exception not thrown");
} catch(Throwable e) {
Assert.assertEquals(expected.getClass(), e.getClass());
if (expected.getMessage() != null) {
Assert.assertEquals(expected.getMessage(), e.getMessage());
}
}
}
@Test
public void testNextPrime() {
Assert.assertEquals(2, Primes.nextPrime(0));
Assert.assertEquals(2, Primes.nextPrime(1));
Assert.assertEquals(2, Primes.nextPrime(2));
Assert.assertEquals(3, Primes.nextPrime(3));
Assert.assertEquals(5, Primes.nextPrime(4));
Assert.assertEquals(5, Primes.nextPrime(5));
for (int i = 0; i < SmallPrimes.PRIMES.length - 1; i++) {
for (int j = SmallPrimes.PRIMES[i] + 1; j <= SmallPrimes.PRIMES[i + 1]; j++) {
Assert.assertEquals(SmallPrimes.PRIMES[i+1], Primes.nextPrime(j));
}
}
Assert.assertEquals(25325981, Primes.nextPrime(25325981));
for (int i = 25325981 + 1; i <= 25326023; i++) {
Assert.assertEquals(25326023, Primes.nextPrime(i));
}
Assert.assertEquals(Integer.MAX_VALUE, Primes.nextPrime(Integer.MAX_VALUE - 10));
Assert.assertEquals(Integer.MAX_VALUE, Primes.nextPrime(Integer.MAX_VALUE - 1));
Assert.assertEquals(Integer.MAX_VALUE, Primes.nextPrime(Integer.MAX_VALUE));
assertNextPrimeException(Integer.MIN_VALUE, new MathIllegalArgumentException(LocalizedFormats.NUMBER_TOO_SMALL,Integer.MIN_VALUE,0));
assertNextPrimeException(-1, new MathIllegalArgumentException(LocalizedFormats.NUMBER_TOO_SMALL,-1,0));
assertNextPrimeException(-13, new MathIllegalArgumentException(LocalizedFormats.NUMBER_TOO_SMALL,-13,0));
}
@Test
public void testIsPrime() throws Exception {
for (int i : BELOW_2) {
Assert.assertFalse(Primes.isPrime(i));
}
for (int i:NOT_PRIMES) {
Assert.assertFalse(Primes.isPrime(i));
}
for (int i:PRIMES) {
Assert.assertTrue(Primes.isPrime(i));
}
}
static int sum(List<Integer> numbers){
int out = 0;
for (int i:numbers) {
out += i;
}
return out;
}
static int product(List<Integer> numbers) {
int out = 1;
for (int i : numbers) {
out *= i;
}
return out;
}
static final HashSet<Integer> PRIMES_SET = new HashSet<>();
static {
for (int p : PRIMES) {
PRIMES_SET.add(p);
}
}
static void checkPrimeFactors(List<Integer> factors){
for (int p : factors) {
if (!PRIMES_SET.contains(p)) {
Assert.fail("Not found in primes list: " + p);
}
}
}
@Test
public void testPrimeFactors() throws Exception {
for (int i : BELOW_2) {
assertPrimeFactorsException(i, new MathIllegalArgumentException(LocalizedFormats.NUMBER_TOO_SMALL,i,2));
}
for (int i : NOT_PRIMES) {
List<Integer> factors = Primes.primeFactors(i);
checkPrimeFactors(factors);
int prod = product(factors);
Assert.assertEquals(i, prod);
}
for (int i : PRIMES) {
List<Integer> factors = Primes.primeFactors(i);
Assert.assertEquals(i, (int)factors.get(0));
Assert.assertEquals(1, factors.size());
}
}
}