Adding comparison test

.phpunit.result.cache

@@ -1 +1 @@
-{"version":2,"defects":{"PrimeNumberTest::testIsPrime":8,"PrimeNumberTest::testModPow":8,"PrimeNumberTest::testLargePrimeNumbers":8,"PrimeNumberTest::testEdgeCases":8,"IntegerTest::testIntegerValidations":7,"IntegerTest::testDivisionByBiggerDivisorException":7,"PrimeGeneratorTest::testGeneratePrime":7,"PrimeGeneratorTest::testPrimeGenerationPerformance":8,"PrimeGeneratorTest::testLargePrimeGeneration":8},"times":{"IntegerTest::testIntegerValidations":0.002,"IntegerTest::testInvalidNumberException":0,"IntegerTest::testCreateDefault":0,"IntegerTest::testCreateByInt":0,"IntegerTest::testCreateByString":0,"IntegerTest::testPrint":0,"IntegerTest::testAdd":0.083,"IntegerTest::testLargeAddition":0,"IntegerTest::testSubtract":0.082,"IntegerTest::testLargeSubtraction":0,"IntegerTest::testNegativeSubtraction":0,"IntegerTest::testSubtractWithNegativeResults":0.172,"IntegerTest::testLargeNegativeSubtraction":0,"IntegerTest::testMultiplyByInt":0,"IntegerTest::testMultiplyByIntException":0,"IntegerTest::testMultiply":0.428,"IntegerTest::testGreaterThan":0.049,"IntegerTest::testGreaterOrEqualTo":0,"IntegerTest::testStringLength":14.224,"IntegerTest::testMaximumMultiplier":0.026,"IntegerTest::testMaxMultiplierException":0,"IntegerTest::testNumberLength":0,"IntegerTest::testDivision":0.003,"IntegerTest::testDivisionByZeroException":0,"IntegerTest::testDivisionByBiggerDivisorException":0,"IntegerTest::testSeveralDivisions":0.064,"IntegerTest::testModule":0.001,"IntegerTest::testCreatingLargeNumber":0.001,"PrimeNumberTest::testIsPrime":0.012,"PrimeNumberTest::testIsProbablePrime":0,"PrimeNumberTest::testModPow":0,"PrimeNumberTest::testGcd":0,"PrimeNumberTest::testLcm":0,"PrimeNumberTest::testLargePrimeNumbers":0.17,"PrimeNumberTest::testEdgeCases":0,"PrimeGeneratorTest::testGenerateRandomOdd":0,"PrimeGeneratorTest::testGeneratePrime":0.415,"PrimeGeneratorTest::testGeneratePrimeSmallBits":0.013,"PrimeGeneratorTest::testGenerateTwinPrimes":0.355,"PrimeGeneratorTest::testGenerateNextPrime":0.007,"PrimeGeneratorTest::testGeneratePrimesInRange":0.029,"PrimeGeneratorTest::testGenerateRandomPrimeInRange":0.01,"PrimeGeneratorTest::testGenerateSophieGermainPrime":0.745,"PrimeGeneratorTest::testInvalidBitLength":0,"PrimeGeneratorTest::testInvalidBitLengthRandomOdd":0,"PrimeGeneratorTest::testPrimeGenerationPerformance":0.525,"PrimeGeneratorTest::testLargePrimeGeneration":1.584,"PrimeGeneratorTest::testPrimeProperties":0.499}}
+{"version":2,"defects":{"PrimeNumberTest::testIsPrime":8,"PrimeNumberTest::testModPow":8,"PrimeNumberTest::testLargePrimeNumbers":8,"PrimeNumberTest::testEdgeCases":8,"IntegerTest::testIntegerValidations":7,"IntegerTest::testDivisionByBiggerDivisorException":7,"PrimeGeneratorTest::testGeneratePrime":7,"PrimeGeneratorTest::testPrimeGenerationPerformance":8,"PrimeGeneratorTest::testLargePrimeGeneration":8,"PrimalityComparisonTest::testSmallNumberComparison":7},"times":{"IntegerTest::testIntegerValidations":0.002,"IntegerTest::testInvalidNumberException":0,"IntegerTest::testCreateDefault":0,"IntegerTest::testCreateByInt":0,"IntegerTest::testCreateByString":0,"IntegerTest::testPrint":0,"IntegerTest::testAdd":0.082,"IntegerTest::testLargeAddition":0,"IntegerTest::testSubtract":0.082,"IntegerTest::testLargeSubtraction":0,"IntegerTest::testNegativeSubtraction":0,"IntegerTest::testSubtractWithNegativeResults":0.176,"IntegerTest::testLargeNegativeSubtraction":0,"IntegerTest::testMultiplyByInt":0,"IntegerTest::testMultiplyByIntException":0,"IntegerTest::testMultiply":0.397,"IntegerTest::testGreaterThan":0.048,"IntegerTest::testGreaterOrEqualTo":0,"IntegerTest::testStringLength":14.207,"IntegerTest::testMaximumMultiplier":0.026,"IntegerTest::testMaxMultiplierException":0,"IntegerTest::testNumberLength":0,"IntegerTest::testDivision":0.002,"IntegerTest::testDivisionByZeroException":0,"IntegerTest::testDivisionByBiggerDivisorException":0,"IntegerTest::testSeveralDivisions":0.064,"IntegerTest::testModule":0,"IntegerTest::testCreatingLargeNumber":0.001,"PrimeNumberTest::testIsPrime":0.015,"PrimeNumberTest::testIsProbablePrime":0,"PrimeNumberTest::testModPow":0,"PrimeNumberTest::testGcd":0,"PrimeNumberTest::testLcm":0.001,"PrimeNumberTest::testLargePrimeNumbers":0.184,"PrimeNumberTest::testEdgeCases":0,"PrimeGeneratorTest::testGenerateRandomOdd":0,"PrimeGeneratorTest::testGeneratePrime":0.476,"PrimeGeneratorTest::testGeneratePrimeSmallBits":0.012,"PrimeGeneratorTest::testGenerateTwinPrimes":0.273,"PrimeGeneratorTest::testGenerateNextPrime":0.007,"PrimeGeneratorTest::testGeneratePrimesInRange":0.033,"PrimeGeneratorTest::testGenerateRandomPrimeInRange":0.012,"PrimeGeneratorTest::testGenerateSophieGermainPrime":0.197,"PrimeGeneratorTest::testInvalidBitLength":0,"PrimeGeneratorTest::testInvalidBitLengthRandomOdd":0,"PrimeGeneratorTest::testPrimeGenerationPerformance":0.424,"PrimeGeneratorTest::testLargePrimeGeneration":1.592,"PrimeGeneratorTest::testPrimeProperties":0.388,"PrimalityComparisonTest::testSmallNumberComparison":0.004,"PrimalityComparisonTest::testMediumNumberComparison":1.813,"PrimalityComparisonTest::testLargeNumberProbabilisticOnly":1.038,"PrimalityComparisonTest::testAccuracyComparison":0.008}}

src/thehappycat/numerictools/Integer.php

@@ -641,6 +641,41 @@ public function isPrime(): bool
         return $this->isProbablePrime(20);
     }
 
+    /**
+     * Brute force primality test - tests every possible divisor
+     * WARNING: Extremely slow for large numbers!
+     * 
+     * @return bool
+     */
+    public function isPrimeBruteForce(): bool
+    {
+        if ($this->isNegative() || $this->isZero() || $this->getStringValue() === '1') {
+            return false;
+        }
+
+        if ($this->getStringValue() === '2' || $this->getStringValue() === '3') {
+            return true;
+        }
+
+        // Check if even
+        if ($this->mod(Integer::createByInt(2))->isZero()) {
+            return false;
+        }
+
+        $sqrt = $this->sqrt();
+        $divisor = Integer::createByInt(3);
+
+        // Test odd divisors up to √n
+        while ($divisor->lessThanOrEqualTo($sqrt)) {
+            if ($this->mod($divisor)->isZero()) {
+                return false; // Found a divisor
+            }
+            $divisor = $divisor->add(Integer::createByInt(2));
+        }
+
+        return true; // No divisors found
+    }
+
     /**
      * Check if this number is less than or equal to another number
      * 

tests/PrimalityComparisonTest.php

@@ -0,0 +1,163 @@
+<?php
+
+require_once __DIR__ . '/../vendor/autoload.php';
+
+use PHPUnit\Framework\TestCase;
+use TheHappyCat\NumericTools\Integer;
+
+/**
+ * Class PrimalityComparisonTest
+ * Compares performance of probabilistic vs brute force primality testing
+ */
+class PrimalityComparisonTest extends TestCase
+{
+    public function testSmallNumberComparison()
+    {
+        $number = Integer::createByString('97'); // Known prime
+
+        echo "\n=== Testing Small Number (97) ===\n";
+
+        // Test probabilistic method
+        $start = microtime(true);
+        $probResult = $number->isProbablePrime(5);
+        $probTime = (microtime(true) - $start) * 1000;
+
+        // Test brute force method
+        $start = microtime(true);
+        $bruteResult = $number->isPrimeBruteForce();
+        $bruteTime = (microtime(true) - $start) * 1000;
+
+        echo "Probabilistic: " . ($probResult ? "Prime" : "Composite") . " in " . round($probTime, 2) . "ms\n";
+        echo "Brute Force: " . ($bruteResult ? "Prime" : "Composite") . " in " . round($bruteTime, 2) . "ms\n";
+        echo "Speedup: " . round($bruteTime / $probTime, 1) . "x faster\n";
+
+        $this->assertTrue($probResult);
+        $this->assertTrue($bruteResult);
+
+        // For small numbers, both should be fast (under 100ms in CI environment)
+        $this->assertTrue($probTime < 100, "Probabilistic test took too long: {$probTime}ms");
+        $this->assertTrue($bruteTime < 100, "Brute force test took too long: {$bruteTime}ms");
+
+        // Both methods should give correct results
+        $this->assertTrue($probResult === $bruteResult, "Results should match");
+    }
+
+    public function testMediumNumberComparison()
+    {
+        $number = Integer::createByString('1000000007'); // Known prime
+
+        echo "\n=== Testing Medium Number (1000000007) ===\n";
+
+        // Test probabilistic method
+        $start = microtime(true);
+        $probResult = $number->isProbablePrime(5);
+        $probTime = (microtime(true) - $start) * 1000;
+
+        // Test brute force method (this will take a while!)
+        echo "Running brute force test (this may take several minutes)...\n";
+        $start = microtime(true);
+        $bruteResult = $number->isPrimeBruteForce();
+        $bruteTime = (microtime(true) - $start) * 1000;
+
+        echo "Probabilistic: " . ($probResult ? "Prime" : "Composite") . " in " . round($probTime, 2) . "ms\n";
+        echo "Brute Force: " . ($bruteResult ? "Prime" : "Composite") . " in " . round($bruteTime, 2) . "ms\n";
+        echo "Speedup: " . round($bruteTime / $probTime, 1) . "x faster\n";
+
+        $this->assertTrue($probResult);
+        $this->assertTrue($bruteResult);
+
+        // For medium numbers, probabilistic should be significantly faster
+        // Allow for some variance in CI environments
+        $this->assertTrue($probTime < $bruteTime * 0.8, "Probabilistic should be faster for medium numbers");
+
+        // Both methods should give correct results
+        $this->assertTrue($probResult === $bruteResult, "Results should match");
+    }
+
+    public function testLargeNumberProbabilisticOnly()
+    {
+        $number = Integer::createByString('123456789012345678901234567890123456789');
+
+        echo "\n=== Testing Large Number (Probabilistic Only) ===\n";
+
+        // Only test probabilistic method for large numbers
+        $start = microtime(true);
+        $probResult = $number->isProbablePrime(10);
+        $probTime = (microtime(true) - $start) * 1000;
+
+        echo "Number: " . $number->getStringValue() . "\n";
+        echo "Digits: " . $number->getLength() . "\n";
+        echo "Probabilistic: " . ($probResult ? "Prime" : "Composite") . " in " . round($probTime, 2) . "ms\n";
+        echo "Brute Force: Would take approximately " . calculateBruteForceTime($number) . "\n";
+
+        // Don't test brute force - it would take too long!
+        $this->assertIsBool($probResult);
+    }
+
+    public function testAccuracyComparison()
+    {
+        echo "\n=== Testing Accuracy ===\n";
+
+        // Test known primes
+        $knownPrimes = ['2', '3', '5', '7', '11', '13', '17', '19', '23', '29', '31', '37'];
+        $knownComposites = ['4', '6', '8', '9', '10', '12', '14', '15', '16', '18', '20', '21'];
+
+        $probCorrect = 0;
+        $bruteCorrect = 0;
+        $total = count($knownPrimes) + count($knownComposites);
+
+        // Test primes
+        foreach ($knownPrimes as $primeStr) {
+            $number = Integer::createByString($primeStr);
+            $probResult = $number->isProbablePrime(5);
+            $bruteResult = $number->isPrimeBruteForce();
+
+            if ($probResult) $probCorrect++;
+            if ($bruteResult) $bruteCorrect++;
+        }
+
+        // Test composites
+        foreach ($knownComposites as $compositeStr) {
+            $number = Integer::createByString($compositeStr);
+            $probResult = $number->isProbablePrime(5);
+            $bruteResult = $number->isPrimeBruteForce();
+
+            if (!$probResult) $probCorrect++;
+            if (!$bruteResult) $bruteCorrect++;
+        }
+
+        $probAccuracy = ($probCorrect / $total) * 100;
+        $bruteAccuracy = ($bruteCorrect / $total) * 100;
+
+        echo "Probabilistic Accuracy: " . round($probAccuracy, 1) . "%\n";
+        echo "Brute Force Accuracy: " . round($bruteAccuracy, 1) . "%\n";
+
+        $this->assertEquals(100, $bruteAccuracy); // Brute force should be 100% accurate
+        $this->assertGreaterThan(95, $probAccuracy); // Probabilistic should be >95% accurate
+    }
+}
+
+/**
+ * Calculate estimated time for brute force primality test
+ * This is a rough approximation based on number size
+ */
+function calculateBruteForceTime(Integer $number): string
+{
+    $digits = $number->getLength();
+
+    // Rough approximation: O(√n) operations
+    // For n digits, √n ≈ 10^(n/2)
+    // Assuming each operation takes ~1 microsecond
+
+    if ($digits <= 10) {
+        return "seconds";
+    } elseif ($digits <= 20) {
+        return "minutes";
+    } elseif ($digits <= 30) {
+        return "hours";
+    } elseif ($digits <= 40) {
+        return "days";
+    } else {
+        return "years or more";
+    }
+}