From 8e1ec78f74875f3fd5f1b944953a78a8b1c2cafa Mon Sep 17 00:00:00 2001
From: Akumatic <ugp@hotmail.de>
Date: Tue, 19 Nov 2019 19:27:35 +0100
Subject: [PATCH] Added 2018 day 12

---
 2018/day12.py        | 123 +++++++++++++++++++++++++++++++++++++++++++
 2018/input/day12.txt |  34 ++++++++++++
 2 files changed, 157 insertions(+)
 create mode 100644 2018/day12.py
 create mode 100644 2018/input/day12.txt

diff --git a/2018/day12.py b/2018/day12.py
new file mode 100644
index 0000000..6f9e175
--- /dev/null
+++ b/2018/day12.py
@@ -0,0 +1,123 @@
+""" https://adventofcode.com/2018/day/5 """
+
+def readFile():
+    import os.path as p
+    dName = p.dirname(__file__)
+    fName = p.basename(__file__).split(".")[0]
+
+    with open(p.join(dName, "input", f"{fName}.txt"), "r") as f:
+        lines = [line[:-1] for line in f.readlines()]
+    state = list(lines[0][15:])
+    rules = [Rule(line) for line in lines[2:] if line[9] == "#"]
+    return (state, rules)
+
+def getTest():
+    stateString = "initial state: ...#..#.#..##......###...###..........."
+    ruleStrings = ["...## => #", "..#.. => #", ".#... => #", ".#.#. => #", 
+        ".#.## => #", ".##.. => #", ".#### => #", "#.#.# => #", "#.### => #", 
+        "##.#. => #", "##.## => #", "###.. => #", "###.# => #", "####. => #"]
+    state = list(stateString[15:])
+    rules = [Rule(rule) for rule in ruleStrings]
+    return (state, rules)
+
+class Rule:
+    def __init__(self, string):
+        self.left = string[:2]
+        self.center = string[2]
+        self.right = string[3:5]
+        self.rule = list(self.left + self.center + self.right)
+        self.result = string[9]
+
+    def compare(self, state):
+        return self.rule == state
+
+def part1(vals, generations, offset = 0, printGen = False):
+    generation = vals[0]
+    pad = ["."]
+
+    if generation[-1] == "#":
+        generation += [".", "."]
+    elif generation[-2] == "#":
+        generation.append(".")
+
+    if printGen:
+        print(f" 0: {''.join(generation)}")
+
+    for i in range(generations):
+        size = len(generation)
+        cur = ["." for j in range(size)]
+        for j in range(size):
+            if j < 2: # pad left side with empty pods
+                temp = pad*(2 - j) + generation[:(3 + j)]
+            elif j > size - 3: # pad right side with empty pods
+                diff = size - j
+                temp = generation[(size-2-diff):] + pad*(3-diff)
+            else:
+                temp = generation[j-2:j+3]
+            
+            for rule in vals[1]:
+                if rule.compare(temp):
+                    cur[j] = rule.result
+                    break
+        
+        if cur[-1] == "#":
+            cur += [".", "."]
+        elif cur[-2] == "#":
+            cur.append(".")
+
+        generation = cur
+
+        if printGen:
+            print(f"{i + 1 if i + 1 > 9 else f' {i + 1}'}: {''.join(generation)}")
+    
+    return sum(i - offset for i in range(len(generation)) if generation[i] == "#")
+
+def part2(vals, generations, offset = 0):
+    generation = vals[0]
+    pad = ["."]
+
+    genSum = sum(i - offset for i in range(len(generation)) if generation[i] == "#")
+
+    if generation[-1] == "#":
+        generation += [".", "."]
+    elif generation[-2] == "#":
+        generation.append(".")
+
+    i = 0
+    while True:
+        i += 1
+        size = len(generation)
+        cur = ["." for j in range(size)]
+        for j in range(size):
+            if j < 2: # pad left side with empty pods
+                temp = pad*(2 - j) + generation[:(3 + j)]
+            elif j > size - 3: # pad right side with empty pods
+                diff = size - j
+                temp = generation[(size-2-diff):] + pad*(3-diff)
+            else:
+                temp = generation[j-2:j+3]
+            
+            for rule in vals[1]:
+                if rule.compare(temp):
+                    cur[j] = rule.result
+                    break
+        
+        if cur[-1] == "#":
+            cur += [".", "."]
+        elif cur[-2] == "#":
+            cur.append(".")
+
+        generation = cur
+
+        curSum = sum(i - offset for i in range(len(cur)) if cur[i] == "#")
+        if curSum - genSum == 52:
+            break
+        genSum = curSum
+
+    return curSum + 52*(generations - i)
+
+if __name__ == "__main__":
+    print(f"Test:   {part1(getTest(), generations=20, offset=3, printGen=True)}")
+    vals = readFile()
+    print(f"Part 1: {part1(vals, generations=20)}")
+    print(f"Part 2: {part2(vals, generations=5*10**10)}")
\ No newline at end of file
diff --git a/2018/input/day12.txt b/2018/input/day12.txt
new file mode 100644
index 0000000..30f7084
--- /dev/null
+++ b/2018/input/day12.txt
@@ -0,0 +1,34 @@
+initial state: ###.......##....#.#.#..###.##..##.....#....#.#.....##.###...###.#...###.###.#.###...#.####.##.#....#
+
+..... => .
+#..## => .
+..### => #
+..#.# => #
+.#.#. => .
+####. => .
+##.## => #
+#.... => .
+#...# => .
+...## => .
+##..# => .
+.###. => #
+##### => #
+#.#.. => #
+.##.. => #
+.#.## => .
+...#. => #
+#.##. => #
+..#.. => #
+##... => #
+....# => .
+###.# => #
+#..#. => #
+#.### => #
+##.#. => .
+###.. => #
+.#### => .
+.#... => #
+..##. => .
+.##.# => .
+#.#.# => #
+.#..# => .