From 0d077d1f6983cb97620bb0c211b73c52cfcaa3c0 Mon Sep 17 00:00:00 2001
From: Fangyu Gai <greferry@gmail.com>
Date: Wed, 10 Oct 2018 22:57:44 -0700
Subject: [PATCH] Add data migration

---
 python/09_queue/array_queue.py | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/python/09_queue/array_queue.py b/python/09_queue/array_queue.py
index 40f34c2..1b1252e 100644
--- a/python/09_queue/array_queue.py
+++ b/python/09_queue/array_queue.py
@@ -16,9 +16,16 @@ class ArrayQueue:
         self._tail = 0
 
     def enqueue(self, item: str) -> bool:
-        if self._tail == self._capacity: return False
+        if self._tail == self._capacity:
+            if self._head == 0:
+                return False
+            else:
+                for i in range(0, self._tail - self._head):
+                    self._data[i] = self._items[i + self._head]
+                self._tail = self._tail - self._head
+                self._head = 0
         
-        self._items.append(item)
+        self._items.insert(self._tail, item)
         self._tail += 1
         return True