Duplicates in subsets

Author: ParthDhavan04

Arrays/SubsetDup.java

@@ -0,0 +1,23 @@
+//duplicate elements' subset eg [1,2,2]
+static List<List<Integer>> subsetDuplicate(int[] arr) {
+        Arrays.sort(arr);
+        List<List<Integer>> outer = new ArrayList<>();
+        outer.add(new ArrayList<>());
+        int start = 0;
+        int end = 0;
+        for (int i = 0; i < arr.length; i++) {
+            start = 0;
+            // if current and previous element is same, s = e + 1
+            if (i > 0 && arr[i] == arr[i-1]) {
+                start = end + 1;
+            }
+            end = outer.size() - 1;
+            int n = outer.size();
+            for (int j = start; j < n; j++) {
+                List<Integer> internal = new ArrayList<>(outer.get(j));
+                internal.add(arr[i]);
+                outer.add(internal);
+            }
+        }
+        return outer;
+    }