1 files changed, 36 insertions, 0 deletions
diff --git a/challenge-306/roger-bell-west/python/ch-1.py b/challenge-306/roger-bell-west/python/ch-1.py
new file mode 100755
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+++ b/challenge-306/roger-bell-west/python/ch-1.py
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+#! /usr/bin/python3
+
+import collections
+from itertools import islice
+
+# https://docs.python.org/3/library/itertools.html
+def sliding_window(iterable, n):
+    # sliding_window('ABCDEFG', 4) --> ABCD BCDE CDEF DEFG
+    it = iter(iterable)
+    window = collections.deque(islice(it, n), maxlen=n)
+    if len(window) == n:
+        yield tuple(window)
+    for x in it:
+        window.append(x)
+        yield tuple(window)
+
+def oddsum(a):
+  out = sum(a)
+  l = 3
+  while l <= len(a):
+    for s in sliding_window(a, l):
+      out += sum(s)
+    l += 2
+  return out
+
+import unittest
+
+class TestOddsum(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(oddsum([2, 5, 3, 6, 4]), 77, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(oddsum([1, 3]), 4, 'example 2')
+
+unittest.main()