day 12

12/a.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+
+
+def printstate(state):
+    skeys = state.keys()
+    for key in range(-30, max(skeys) + 1):
+        try:
+            print("#" if state[key] else ".", end="")
+        except KeyError:
+            print(".", end="")
+    print()
+
+
+def fmtrule(rule):
+    return "".join(["#" if c else "." for c in rule[0]])
+
+
+def main():
+    state = {}
+    rules = []  # list of ((True, False, True, False, True), True)
+    with open("input.txt") as f:
+        ogstate = f.readline()[15:-1]
+        for i, c in enumerate(ogstate):
+            state[i] = c == "#"
+        f.readline()
+        for line in f.readlines():
+            tf = []
+            for char in line[0:5]:
+                tf.append(char == "#")
+            rules.append((tuple(tf), line[-2] == "#"))
+
+    printstate(state)
+
+    generations = 0
+    while True:
+        newstate = {}
+        statekeys = state.keys()
+        for scankey in range(min(statekeys) - 2, max(statekeys) + 3):
+            for ruleid, rule in enumerate(rules):
+                matches = True
+                for i, oldgenkey in zip(range(0, 5), range(scankey - 2, scankey + 3)):
+                    if (oldgenkey not in state and rule[0][i]):
+                        matches = False
+                        break
+                    elif (oldgenkey in state and rule[0][i] != state[oldgenkey]):
+                        matches = False
+                        break
+                    # try:
+                    #     if state[oldgenkey] != rule[0][i]:
+                    #         matches = False
+                    #         print("b1")
+                    #         break
+                    # except KeyError as e:
+                    #     if rule[0][i]:
+                    #         print("b2")
+                    #         matches = False
+                    #     break
+                if matches and rule[1]:
+                    newstate[scankey] = rule[1]
+                    break
+        printstate(newstate)
+        state = newstate
+        generations += 1
+        if generations >= 20:
+            break
+
+    print(sum(state.keys()))
+
+
+if __name__ == '__main__':
+    main()

12/b.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+
+
+def main():
+    state = {}
+    rules = []  # list of ((True, False, True, False, True), True)
+    with open("input.txt") as f:
+        ogstate = f.readline()[15:-1]
+        for i, c in enumerate(ogstate):
+            state[i] = c == "#"
+        f.readline()
+        for line in f.readlines():
+            tf = []
+            for char in line[0:5]:
+                tf.append(char == "#")
+
+            if line[-2] != "#":  # turns out these didn't matter...?
+                continue
+            rules.append((tuple(tf), line[-2] == "#"))
+
+    generations = 0
+    target = 50000000000
+    lastvalues = []
+    lastvalue = 0
+
+    while True:
+        newstate = {}
+        statekeys = state.keys()
+        for scankey in range(min(statekeys) - 2, max(statekeys) + 3):
+            for ruleid, rule in enumerate(rules):
+                matches = True
+                for i, oldgenkey in zip(range(0, 5), range(scankey - 2, scankey + 3)):
+                    if (oldgenkey not in state and rule[0][i]):
+                        matches = False
+                        break
+                    elif (oldgenkey in state and rule[0][i] != state[oldgenkey]):
+                        matches = False
+                        break
+                if matches:
+                    newstate[scankey] = rule[1]
+                    break
+        state = newstate
+
+        value = sum(state.keys())
+        lastvalues.append(value - lastvalue)
+        lastvalue = value
+        if len(lastvalues) > 5:
+            if len(set(lastvalues)) == 1:
+                print("Convergence on delta", lastvalues[0], "at generation", generations)
+                remaining = target - generations
+                print(value + lastvalues[0] * (remaining - 1))
+                break
+            lastvalues.pop(0)
+
+        generations += 1
+        if generations >= target:
+            break
+
+
+if __name__ == '__main__':
+    main()

12/input.txt

@@ -0,0 +1,34 @@
+initial state: ##.##..#.#....#.##...###.##.#.#..###.#....##.###.#..###...#.##.#...#.#####.###.##..#######.####..#
+
+.##.. => #
+#...# => .
+####. => #
+##..# => #
+..##. => .
+.###. => .
+..#.# => .
+##### => .
+##.#. => #
+...## => #
+.#.#. => .
+##.## => #
+#.##. => .
+#.... => .
+#..## => .
+..#.. => #
+.#..# => #
+.#.## => #
+...#. => .
+.#... => #
+###.# => #
+#..#. => #
+.#### => #
+#.### => #
+.##.# => #
+#.#.. => .
+###.. => #
+..... => .
+##... => .
+....# => .
+#.#.# => #
+..### => #