day 19, beam search, not mine

d19/solve.py

@@ -0,0 +1,33 @@
+import sys, re, numpy
+
+V = lambda *a: numpy.array(a)
+k = lambda a: tuple(sum(a))
+
+def parse(line):
+    i,a,b,c,d,e,f = map(int, re.findall(r'\d+',line))
+    return (i, (V(0,0,0,a), V(0,0,0,1)),     # Cost and production
+               (V(0,0,0,b), V(0,0,1,0)),     # of each robot type,
+               (V(0,0,d,c), V(0,1,0,0)),     # in the order geode,
+               (V(0,f,0,e), V(1,0,0,0)),     # obs, clay, and ore.
+               (V(0,0,0,0), V(0,0,0,0)))     # Construct no robot.
+
+BEST = int(sys.argv[1])
+def run(blueprint, t):
+    todo = [(V(0,0,0,0), V(0,0,0,1))]        # resources and robots.
+    for _ in range(t):
+        todo_ = list()                       # Queue for the next minute.
+        for have, make in todo:
+            for cost, more in blueprint:
+                if all(have >= cost):        # We can afford this robot.
+                    todo_.append((have+make-cost, make+more))
+        todo = sorted(todo_, key=k)[-BEST:]  # adds resources and robots (k)
+		                                     # the more of both, the better
+		                                     # then prune the search queue
+    return max(todo, key=k)[0][0]
+
+part1, part2 = 0, 1
+for i, *blueprint in map(parse, sys.stdin):
+    part1 += run(blueprint, 24) * i
+    part2 *= run(blueprint, 32) if i<4 else 1
+
+print(part1, part2)