1 files changed, 39 insertions, 0 deletions
diff --git a/challenge-099/roger-bell-west/python/ch-2.py b/challenge-099/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..2acef1cb02
--- /dev/null
+++ b/challenge-099/roger-bell-west/python/ch-2.py
@@ -0,0 +1,39 @@
+#! /usr/bin/python3
+
+from collections import defaultdict
+
+def us(text,match):
+    s=defaultdict(list)
+    for i,c in enumerate(text):
+        s[c].append(i)
+    j=list()
+    for c in match:
+        if c in s:
+            j.append(s[c])
+        else:
+            return 0
+    o=list();
+    for i in range(len(j[0])):
+        o.append(1)
+    for m in range(1,len(j)):
+        n=list()
+        for bi in range(len(j[m])):
+            t=0
+            for ai in range(len(j[m-1])):
+                if j[m-1][ai] < j[m][bi]:
+                    t += o[ai]
+            n.append(t)
+        o=n
+    return sum(o)
+
+import unittest
+
+class TestUs(unittest.TestCase):
+
+    def test_ex1(self):
+        self.assertEqual(us('littleit','lit'),5,'example 1')
+
+    def test_ex2(self):
+        self.assertEqual(us('london','lon'),3,'example 2')
+
+unittest.main()