Add SwapAdjacentBits algorithm (#5634)

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

@@ -0,0 +1,22 @@
+package com.thealgorithms.bitmanipulation;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+class SwapAdjacentBitsTest {
+
+    @ParameterizedTest
+    @CsvSource({
+        "2, 1", // 2 (10 in binary) should become 1 (01 in binary)
+        "43, 23", // 43 should become 23
+        "153, 102", // 153 should become 102
+        "15, 15", // 15 (1111) remains 15 (1111)
+        "0, 0" // 0 (0000) remains 0 (0000)
+    })
+    void
+    testSwapAdjacentBits(int input, int expected) {
+        assertEquals(expected, SwapAdjacentBits.swapAdjacentBits(input));
+    }
+}