Recursion- Return possible subsets of an array

Author: AnushreeBagchi

return-subset.py

@@ -0,0 +1,38 @@
+def subset(arr):
+    output = [[]]
+    window = 1
+    while window < len(arr):
+        window_start = 0
+        while window_start < len(arr):
+            counter = 1
+            window_end = window_start+window
+            while window_end + counter <= len(arr):
+                to_append = []
+                to_append.extend(arr[window_start:window_end])
+                to_append.append(arr[window_end+counter-1])
+                output.append(to_append)
+                counter +=1
+            window_start += 1
+        window += 1    
+    return output
+
+def subset_with_recursion(arr):
+    return return_subset_with_recursion(arr, 0)
+
+def return_subset_with_recursion(arr, index):
+    if index >= len(arr):
+        return [[]]
+    output = list()
+    small_output = return_subset_with_recursion(arr, index+1)
+    for element in small_output:
+        output.append(element)
+    for element in small_output:
+        curr = list()
+        curr.append(arr[index])
+        curr.extend(element)
+        output.append(curr)
+    
+    return output
+
+
+print(subset_with_recursion([9,15,12]))