1 files changed, 47 insertions, 0 deletions
diff --git a/challenge-274/roger-bell-west/python/ch-2.py b/challenge-274/roger-bell-west/python/ch-2.py
new file mode 100755
index 0000000000..fd00b3f58a
--- /dev/null
+++ b/challenge-274/roger-bell-west/python/ch-2.py
@@ -0,0 +1,47 @@
+#! /usr/bin/python3
+
+def busroute(a):
+  routes = []
+  for rt in a:
+    ri = dict()
+    (interval, offset, duration) = rt
+    start = offset
+    while start <= 60 + offset:
+      ri[start] = start + duration
+      start += interval
+    routes.append(ri)
+  out = []
+  for t in range(60):
+    best = set()
+    at = -1
+    nxt = set()
+    ndt = -1
+    for i, r in enumerate(routes):
+      nb = min([n for n in r.keys() if n >= t])
+      nt = r[nb]
+      if at == -1 or nt < at:
+        best.clear()
+        at = nt
+      if nt <= at:
+        best.add(i)
+      if ndt == -1 or nb < ndt:
+        nxt.clear()
+        ndt = nb
+      if nb <= ndt:
+        nxt.add(i)
+    if len(best.intersection(nxt)) == 0:
+      out.append(t)
+  return out
+      
+
+import unittest
+
+class TestBusroute(unittest.TestCase):
+
+  def test_ex1(self):
+    self.assertEqual(busroute([[12, 11, 41], [15, 5, 35]]), [36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47], 'example 1')
+
+  def test_ex2(self):
+    self.assertEqual(busroute([[12, 3, 41], [15, 9, 35], [30, 5, 25]]), [0, 1, 2, 3, 25, 26, 27, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 55, 56, 57, 58, 59], 'example 2')
+
+unittest.main()