1 files changed, 13 insertions, 0 deletions
diff --git a/progs/a660.py b/progs/a660.py
new file mode 100644
index 0000000..341c0fc
--- /dev/null
+++ b/progs/a660.py
@@ -0,0 +1,13 @@
+def flatten_list(list1):
+    result_list = []
+    if not list1: return result_list
+    stack = [list(list1)]
+    while stack:
+        c_num = stack.pop()
+        next = c_num.pop()
+        if c_num: stack.append(c_num)
+        if isinstance(next, list):
+            if next: stack.append(list(next))
+        else: result_list.append(next)
+    result_list.reverse()
+    return result_list 
+\ No newline at end of file