subtree(users/wpcarro): docking briefcase at '24f5a642'

git-subtree-dir: users/wpcarro
git-subtree-mainline: 464bbcb15c
git-subtree-split: 24f5a642af
Change-Id: I6105b3762b79126b3488359c95978cadb3efa789

users/wpcarro/scratch/facebook/interview-cake/queue-two-stacks.py

@@ -0,0 +1,17 @@
+class Queue(object):
+    def __init__(self):
+        self.lhs = []
+        self.rhs = []
+
+    def enqueue(self, x):
+        self.lhs.append(x)
+
+    def dequeue(self):
+        if self.rhs:
+            return self.rhs.pop()
+        while self.lhs:
+            self.rhs.append(self.lhs.pop())
+        if self.rhs:
+            return self.rhs.pop()
+        else:
+            raise Exception("Attempting to remove an item from an empty queue")