Add function documentation, enhance comments in TowerOfHanoi.java (#5533)

src/test/java/com/thealgorithms/others/TowerOfHanoiTest.java

@@ -0,0 +1,50 @@
+package com.thealgorithms.others;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+public class TowerOfHanoiTest {
+
+    @Test
+    public void testHanoiWithOneDisc() {
+        List<String> result = new ArrayList<>();
+        TowerOfHanoi.shift(1, "Pole1", "Pole2", "Pole3", result);
+
+        // Expected output for 1 disc
+        List<String> expected = List.of("Move 1 from Pole1 to Pole3");
+        assertEquals(expected, result);
+    }
+
+    @Test
+    public void testHanoiWithTwoDiscs() {
+        List<String> result = new ArrayList<>();
+        TowerOfHanoi.shift(2, "Pole1", "Pole2", "Pole3", result);
+
+        // Expected output for 2 discs
+        List<String> expected = List.of("Move 1 from Pole1 to Pole2", "Move 2 from Pole1 to Pole3", "Move 1 from Pole2 to Pole3");
+        assertEquals(expected, result);
+    }
+
+    @Test
+    public void testHanoiWithThreeDiscs() {
+        List<String> result = new ArrayList<>();
+        TowerOfHanoi.shift(3, "Pole1", "Pole2", "Pole3", result);
+
+        // Expected output for 3 discs
+        List<String> expected = List.of("Move 1 from Pole1 to Pole3", "Move 2 from Pole1 to Pole2", "Move 1 from Pole3 to Pole2", "Move 3 from Pole1 to Pole3", "Move 1 from Pole2 to Pole1", "Move 2 from Pole2 to Pole3", "Move 1 from Pole1 to Pole3");
+        assertEquals(expected, result);
+    }
+
+    @Test
+    public void testHanoiWithZeroDiscs() {
+        List<String> result = new ArrayList<>();
+        TowerOfHanoi.shift(0, "Pole1", "Pole2", "Pole3", result);
+
+        // There should be no moves if there are 0 discs
+        assertTrue(result.isEmpty());
+    }
+}