Commit 64b0dd1

@@ -0,0 +1,27 @@
+│   Implement a class for a stack that supports all the regular
+│functions
+│   (push, pop) and an additional function of max() which returns
+│the
+│   maximum element in the stack (return None if the stack is
+│empty). Each
+│   method should run in constant time.
+│class MaxStack:
+│  def __init__(self):
+│    # Fill this in.
+│  def push(self, val):
+│    # Fill this in.
+│  def pop(self):
+│    # Fill this in.
+│  def max(self):
+│    # Fill this in.
+│s = MaxStack()
+│s.push(1)
+│s.push(2)
+│s.push(3)
+│s.push(2)
+│print s.max()
+│# 3
+│s.pop()
+│s.pop()
+│print s.max()
+│# 2