testing: improve test coverage ParityCheckTest (#6389)

testing: improve test coverage ParityCheckTest

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

Author: alxkm

src/test/java/com/thealgorithms/bitmanipulation/ParityCheckTest.java

@@ -6,10 +6,30 @@
 import org.junit.jupiter.api.Test;
 
 public class ParityCheckTest {
+    @Test
+    public void testIsEvenParity() {
+        assertTrue(ParityCheck.checkParity(0)); // 0 -> 0 ones
+        assertTrue(ParityCheck.checkParity(3)); // 11 -> 2 ones
+        assertTrue(ParityCheck.checkParity(5)); // 101 -> 2 ones
+        assertTrue(ParityCheck.checkParity(10)); // 1010 -> 2 ones
+        assertTrue(ParityCheck.checkParity(15)); // 1111 -> 4 ones
+        assertTrue(ParityCheck.checkParity(1023)); // 10 ones
+    }
+
     @Test
     public void testIsOddParity() {
-        assertTrue(ParityCheck.checkParity(5)); // 101 has 2 ones (even parity)
-        assertFalse(ParityCheck.checkParity(7)); // 111 has 3 ones (odd parity)
-        assertFalse(ParityCheck.checkParity(8)); // 1000 has 1 one (odd parity)
+        assertFalse(ParityCheck.checkParity(1)); // 1 -> 1 one
+        assertFalse(ParityCheck.checkParity(2)); // 10 -> 1 one
+        assertFalse(ParityCheck.checkParity(7)); // 111 -> 3 ones
+        assertFalse(ParityCheck.checkParity(8)); // 1000 -> 1 one
+        assertFalse(ParityCheck.checkParity(11)); // 1011 -> 3 ones
+        assertFalse(ParityCheck.checkParity(31)); // 11111 -> 5 ones
+    }
+
+    @Test
+    public void testLargeNumbers() {
+        assertTrue(ParityCheck.checkParity(0b10101010)); // 4 ones
+        assertFalse(ParityCheck.checkParity(0b100000000)); // 1 one
+        assertTrue(ParityCheck.checkParity(0xAAAAAAAA)); // Alternating bits, 16 ones
     }
 }