用栈实现队列

yingl · yingl · commit 64a1fc93dac4 · 2016-07-26T14:42:56.000+08:00
diff --git a/implement_queue_by_two_stacks.py b/implement_queue_by_two_stacks.py
@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+
+class MyQueue:
+
+    def __init__(self):
+        self.stack1 = []
+        self.stack2 = []
+        
+    def push(self, element):
+        # write your code here
+        while self.stack1:
+            self.stack2.append(self.stack1.pop())
+        self.stack1.append(element)
+        while self.stack2:
+            self.stack1.append(self.stack2.pop())
+
+    def top(self):
+        # write your code here
+        # return the top element
+        if self.stack1:
+            return self.stack1[-1]
+
+    def pop(self):
+        # write your code here
+        # pop and return the top element
+        return self.stack1.pop()
