Initial data commit

Task/Knapsack-problem-Bounded/Python/knapsack-problem-bounded-1.py

@@ -0,0 +1,51 @@
+from itertools import groupby
+from collections import namedtuple
+
+def anyvalidcomb(items, maxwt, val=0, wt=0):
+    ' All combinations below the maxwt '
+    if not items:
+        yield [], val, wt
+    else:
+        this, *items = items            # car, cdr
+        for n in range(this.number + 1):
+            w = wt  + n * this.weight
+            if w > maxwt:
+                break
+            v = val + n * this.value
+            this_comb = [this] * n
+            for comb, value, weight in anyvalidcomb(items, maxwt, v, w):
+                yield this_comb + comb, value, weight
+
+maxwt = 400
+COMB, VAL, WT = range(3)
+Item  = namedtuple('Items', 'name weight value number')
+items = [ Item(*x) for x in
+          (
+            ("map", 9, 150, 1),
+            ("compass", 13, 35, 1),
+            ("water", 153, 200, 3),
+            ("sandwich", 50, 60, 2),
+            ("glucose", 15, 60, 2),
+            ("tin", 68, 45, 3),
+            ("banana", 27, 60, 3),
+            ("apple", 39, 40, 3),
+            ("cheese", 23, 30, 1),
+            ("beer", 52, 10, 3),
+            ("suntan cream", 11, 70, 1),
+            ("camera", 32, 30, 1),
+            ("t-shirt", 24, 15, 2),
+            ("trousers", 48, 10, 2),
+            ("umbrella", 73, 40, 1),
+            ("waterproof trousers", 42, 70, 1),
+            ("waterproof overclothes", 43, 75, 1),
+            ("note-case", 22, 80, 1),
+            ("sunglasses", 7, 20, 1),
+            ("towel", 18, 12, 2),
+            ("socks", 4, 50, 1),
+            ("book", 30, 10, 2),
+           ) ]
+
+bagged = max( anyvalidcomb(items, maxwt), key=lambda c: (c[VAL], -c[WT])) # max val or min wt if values equal
+print("Bagged the following %i items" % len(bagged[COMB]))
+print('\n\t'.join('%i off: %s' % (len(list(grp)), item.name) for item, grp in groupby(sorted(bagged[COMB]))))
+print("for a total value of %i and a total weight of %i" % bagged[1:])