add subsets

Recursion/Subset.java

@@ -0,0 +1,42 @@
+import java.util.*;
+
+public class Subset {
+
+    public static void printSubset(int currentIndex, List<Integer> ds, int[] nums, int n, List<List<Integer>> finalAnswer){
+        if (currentIndex == n){
+            finalAnswer.add(new ArrayList<>(ds));
+            return;
+        }
+
+        ds.add(nums[currentIndex]);
+        printSubset(currentIndex + 1, ds, nums, n, finalAnswer);
+
+        ds.remove(ds.size() - 1);
+        printSubset(currentIndex + 1, ds, nums, n, finalAnswer);
+    }
+
+    public List<List<Integer>> subsets(int[] nums) {
+        int n = nums.length;
+        List<Integer> ds = new ArrayList<>();
+        List<List<Integer>> finalAnswer = new ArrayList<>();
+
+        printSubset(0, ds, nums, n, finalAnswer);
+
+        return finalAnswer;
+    }
+
+    // -------- DRIVER CODE --------
+    public static void main(String[] args) {
+
+        // Assumed Input
+        int[] nums = {1, 2, 3};
+
+        Solution sol = new Solution();
+        List<List<Integer>> result = sol.subsets(nums);
+
+        System.out.println("Subsets:");
+        for (List<Integer> subset : result) {
+            System.out.println(subset);
+        }
+    }
+}

Recursion/SubsetsWithoutDuplicates.java

@@ -0,0 +1,51 @@
+import java.util.*;
+
+class SubsetsWithoutDuplicates {
+
+    public static void printSubset(int currentIndex, List<Integer> ds, int[] nums, int n, List<List<Integer>> finalAnswer){
+        if (currentIndex == n){
+            finalAnswer.add(new ArrayList<>(ds));
+            return;
+        }
+         
+        // Include
+        ds.add(nums[currentIndex]);
+        printSubset(currentIndex + 1, ds, nums, n, finalAnswer);
+        ds.remove(ds.size() - 1);
+
+        // Exclude
+        int nextIndex = currentIndex + 1;
+        while (nextIndex < n && nums[nextIndex] == nums[currentIndex]){
+            nextIndex++;
+        }
+        printSubset(nextIndex, ds, nums, n, finalAnswer);
+    }
+
+    public List<List<Integer>> subsetsWithDup(int[] nums) {
+
+        Arrays.sort(nums);
+
+        int n = nums.length;
+        List<Integer> ds = new ArrayList<Integer>();
+        List<List<Integer>> finalAnswer = new ArrayList<>();
+        printSubset(0, ds, nums, n, finalAnswer);
+        return finalAnswer;
+    }
+}
+
+
+public class Main {
+    public static void main(String[] args) {
+
+        // Assumed Test Input
+        int[] nums = {1, 2, 2};
+
+        Solution sol = new Solution();
+        List<List<Integer>> result = sol.subsetsWithDup(nums);
+
+        System.out.println("Subsets Without Duplicates:");
+        for (List<Integer> subset : result) {
+            System.out.println(subset);
+        }
+    }
+}