Add GenerateSubsets algorithm (#5867)

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

@@ -0,0 +1,52 @@
+package com.thealgorithms.bitmanipulation;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+class GenerateSubsetsTest {
+
+    @Test
+    void testGenerateSubsetsWithTwoElements() {
+        int[] set = {1, 2};
+        List<List<Integer>> expected = new ArrayList<>();
+        expected.add(new ArrayList<>());
+        expected.add(Arrays.asList(1));
+        expected.add(Arrays.asList(2));
+        expected.add(Arrays.asList(1, 2));
+
+        List<List<Integer>> result = GenerateSubsets.generateSubsets(set);
+        assertEquals(expected, result);
+    }
+
+    @Test
+    void testGenerateSubsetsWithOneElement() {
+        int[] set = {3};
+        List<List<Integer>> expected = new ArrayList<>();
+        expected.add(new ArrayList<>());
+        expected.add(Arrays.asList(3));
+
+        List<List<Integer>> result = GenerateSubsets.generateSubsets(set);
+        assertEquals(expected, result);
+    }
+
+    @Test
+    void testGenerateSubsetsWithThreeElements() {
+        int[] set = {4, 5, 6};
+        List<List<Integer>> expected = new ArrayList<>();
+        expected.add(new ArrayList<>());
+        expected.add(Arrays.asList(4));
+        expected.add(Arrays.asList(5));
+        expected.add(Arrays.asList(4, 5));
+        expected.add(Arrays.asList(6));
+        expected.add(Arrays.asList(4, 6));
+        expected.add(Arrays.asList(5, 6));
+        expected.add(Arrays.asList(4, 5, 6));
+
+        List<List<Integer>> result = GenerateSubsets.generateSubsets(set);
+        assertEquals(expected, result);
+    }
+}