1 files changed, 58 insertions, 0 deletions
diff --git a/challenge-216/roger-bell-west/python/ch-2.py b/challenge-216/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..a55168b8eb
--- /dev/null
+++ b/challenge-216/roger-bell-west/python/ch-2.py
@@ -0,0 +1,58 @@
+#! /usr/bin/python3
+
+from collections import Counter, defaultdict, deque
+from copy import deepcopy
+
+def wordstickers(stickers, word):
+  w = Counter()
+  for c in word:
+    w[c] += 1
+  t = deepcopy(w)
+  stick = []
+  for s in stickers:
+    f = Counter()
+    for c in s.lower():
+      f[c] += 1
+      del t[c]
+    stick.append(f)
+  if len(t) != 0:
+    return 0
+  stack = deque()
+  stack.append((w, 0))
+  while len(stack) > 0:
+    st = stack.popleft()
+    if len(st[0]) == 0:
+      return st[1]
+    else:
+      n = st[1] + 1
+      for sti in stick:
+        sp = deepcopy(st[0])
+        v = False
+        for l in sti.keys():
+          if l in sp:
+            v = True
+            p = sp[l] - sti[l]
+            if p > 0:
+              sp[l] = p
+            else:
+              del sp[l]
+        if v:
+          stack.append((sp, n))
+
+import unittest
+
+class TestWordstickers(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(wordstickers(["perl", "raku", "python"], "peon"), 2, 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(wordstickers(["love", "hate", "angry"], "goat"), 3, 'example 2')
+
+  def test_ex3(self):
+    self.assertEqual(wordstickers(["come", "nation", "delta"], "accomodation"), 4, 'example 3')
+
+  def test_ex4(self):
+    self.assertEqual(wordstickers(["come", "country", "delta"], "accomodation"), 0, 'example 4')
+
+unittest.main()