Dev: Added Germain and Safe prime utility class (#6611)

* feat: add Germain and Safe prime utility class with unit tests

* refactor the code

* fixed identified bugs

* fixed identified remaining bugs

---------

Co-authored-by: Deniz Altunkapan <93663085+DenizAltunkapan@users.noreply.github.com>

src/test/java/com/thealgorithms/maths/GermainPrimeAndSafePrimeTest.java

@@ -0,0 +1,49 @@
+package com.thealgorithms.maths;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.stream.Stream;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+class GermainPrimeAndSafePrimeTest {
+
+    static Stream<Arguments> provideNumbersForGermainPrimes() {
+        return Stream.of(Arguments.of(2, Boolean.TRUE), Arguments.of(3, Boolean.TRUE), Arguments.of(5, Boolean.TRUE), Arguments.of(11, Boolean.TRUE), Arguments.of(23, Boolean.TRUE), Arguments.of(293, Boolean.TRUE), Arguments.of(4, Boolean.FALSE), Arguments.of(7, Boolean.FALSE),
+            Arguments.of(9, Boolean.FALSE), Arguments.of(1, Boolean.FALSE));
+    }
+
+    static Stream<Arguments> provideNumbersForSafePrimes() {
+        return Stream.of(Arguments.of(5, Boolean.TRUE), Arguments.of(7, Boolean.TRUE), Arguments.of(11, Boolean.TRUE), Arguments.of(23, Boolean.TRUE), Arguments.of(1283, Boolean.TRUE), Arguments.of(4, Boolean.FALSE), Arguments.of(13, Boolean.FALSE), Arguments.of(9, Boolean.FALSE),
+            Arguments.of(1, Boolean.FALSE));
+    }
+
+    static Stream<Integer> provideNegativeNumbers() {
+        return Stream.of(-10, -1, 0);
+    }
+
+    @ParameterizedTest
+    @MethodSource("provideNumbersForGermainPrimes")
+    @DisplayName("Check whether a number is a Germain prime")
+    void testValidGermainPrimes(int number, boolean expected) {
+        assertEquals(expected, GermainPrimeAndSafePrime.isGermainPrime(number));
+    }
+
+    @ParameterizedTest
+    @MethodSource("provideNumbersForSafePrimes")
+    @DisplayName("Check whether a number is a Safe prime")
+    void testValidSafePrimes(int number, boolean expected) {
+        assertEquals(expected, GermainPrimeAndSafePrime.isSafePrime(number));
+    }
+
+    @ParameterizedTest
+    @MethodSource("provideNegativeNumbers")
+    @DisplayName("Negative numbers and zero should throw IllegalArgumentException")
+    void testNegativeNumbersThrowException(int number) {
+        assertThrows(IllegalArgumentException.class, () -> GermainPrimeAndSafePrime.isGermainPrime(number));
+        assertThrows(IllegalArgumentException.class, () -> GermainPrimeAndSafePrime.isSafePrime(number));
+    }
+}