Merge branch '031'

e031.py

@@ -0,0 +1,30 @@
+# -*- coding: utf-8 -*-
+"""
+In England the currency is made up of pound, £, and pence, p, and there are
+eight coins in general circulation:
+    1p, 2p, 5p, 10p, 20p, 50p, £1 (100p) and £2 (200p).
+
+It is possible to make £2 in the following way:
+    1£1 + 150p + 220p + 15p + 12p + 31p
+
+How many different ways can £2 be made using any number of coins?
+"""
+
+def combinations(amount, denominations):
+    total = 0
+    if not denominations:
+        return total
+    denominations = sorted(denominations, reverse=True)
+    for i in range(len(denominations)):
+        d = denominations[i]
+        n = 1
+        while d * n <= amount:
+            if d * n == amount:
+                total += 1
+            total += combinations(amount - (d * n), denominations[i+1:])
+            n += 1
+    return total
+
+if __name__ == '__main__':
+    coins = [200, 100, 50, 20, 10, 5, 2, 1]
+    print combinations(200, coins)