MEDIUM/src/medium/Subsets.java for loop way

fishercoder1534 · fishercoder1534 · commit 7e99a8791b14 · 2016-09-01T07:42:13.000-07:00
diff --git a/MEDIUM/src/medium/Subsets.java b/MEDIUM/src/medium/Subsets.java
@@ -0,0 +1,33 @@
+package medium;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import utils.CommonUtils;
+
+public class Subsets {
+
+    public static void main(String...strings){
+        int[] nums = new int[]{1,2,3};
+        List<List<Integer>> result = subsets(nums);
+        CommonUtils.printIntegerList(result);
+    }
+    
+    public static List<List<Integer>> subsets(int[] nums) {
+        List<List<Integer>> result = new ArrayList();
+        List<Integer> empty = new ArrayList();
+        result.add(empty);
+        if(nums == null) return result;
+        for(int i = 0; i < nums.length; i++){
+            List<List<Integer>> temp = new ArrayList();//you'll have to create a new one here, otherwise, it'll throw ConcurrentModificationException.
+            for(List<Integer> list : result){
+                List<Integer> newList = new ArrayList(list);
+                newList.add(nums[i]);
+                temp.add(newList);
+            }
+            result.addAll(temp);
+        }
+        return result;
+    }
+
+}
