unit4 pro1 version 1 solved

Author: yyl

unit4/pro1.py

@@ -0,0 +1,37 @@
+'''
+Write a visitor to solve each of the following problems:
+  1. Find the smallest element of a list.
+  2. Find the largest element of a list.
+  3. Compute the sum of all the elements of a list.
+  4. Compute the product of all the elements of a list.
+'''
+
+from opus7.orderedListAsArray import OrderedListAsArray
+from opus7.visitor import Visitor
+
+def pro1():
+  order_list = OrderedListAsArray(10)
+  m_visitor = MinimumVisitor()
+  order_list.insert(42)
+  order_list.insert(21)
+  order_list.insert(41)
+  order_list.insert(13)
+  order_list.insert(94)
+  order_list.insert(34)
+  order_list.accept(m_visitor)
+  m_visitor.current()
+
+class MinimumVisitor(Visitor):
+
+  def __init__(self):
+    self.minimum = 9999999999
+
+  def visit(self, obj):
+    if obj < self.minimum:
+      self.minimum = obj
+
+  def current(self):
+    print "current minimum value is:", self.minimum
+
+
+pro1()