Solve 2015 days 20-22.

2015/d21.py

@@ -0,0 +1,89 @@
+from itertools import combinations
+
+data = open(0).read().strip()
+
+# hit points, damage, armor
+enemy = [100, 8, 2]
+
+weapons = [
+    [8, 4, 0],
+    [10, 5, 0],
+    [25, 6, 0],
+    [40, 7, 0],
+    [74, 8, 0],
+]
+
+# Armor:      Cost  Damage  Armor
+armor = [
+    [13, 0, 1],
+    [31, 0, 2],
+    [53, 0, 3],
+    [75, 0, 4],
+    [102, 0, 5],
+]
+
+rings = [
+    [25, 1, 0],
+    [50, 2, 0],
+    [100, 3, 0],
+    [20, 0, 1],
+    [40, 0, 2],
+    [80, 0, 3],
+]
+
+
+def player_configs():
+    for wc, wd, wa in weapons:
+        for ac, ad, aa in armor:
+            for i in range(1, 3):
+                for rgs in combinations(rings, i):
+                    c = wc + ac
+                    d = wd + ad
+                    a = wa + aa
+                    for rc, rd, ra in rgs:
+                        c += rc
+                        d += rd
+                        a += ra
+                    yield (c, d, a)
+            c = wc + ac
+            d = wd + ad
+            a = wa + aa
+            yield (c, d, a)
+        for i in range(1, 3):
+            for rgs in combinations(rings, i):
+                c = wc
+                d = wd
+                a = wa
+                for rc, rd, ra in rgs:
+                    c += rc
+                    d += rd
+                    a += ra
+                yield (c, d, a)
+
+
+def simulate(player, enemey):
+    ppoints, pdamage, parmor = player
+    epoints, edamage, earmor = enemey
+
+    while ppoints > 0 and epoints > 0:
+        epoints -= max(pdamage - earmor, 1)
+        ppoints -= max(edamage - parmor, 1)
+
+    if epoints <= 0:
+        return True
+    return False
+
+
+part_1 = False
+if part_1:
+    min_win = float("inf")
+    for c, d, a in player_configs():
+        if simulate([100, d, a], list(enemy)):
+            min_win = min(c, min_win)
+    print(min_win)
+else:
+    max_loss = 0
+    for c, d, a in player_configs():
+        if not simulate([100, d, a], list(enemy)):
+            max_loss = max(c, max_loss)
+    print(max_loss)