Day 12, part1 only

6 files changed, 209 insertions, 0 deletions

diff --git a/day12/Dockerfile b/day12/Dockerfile
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+++ b/day12/Dockerfile
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+FROM ruby:2.5-slim
+
+WORKDIR /opt
+
+COPY . .
+
+ENTRYPOINT ["./entrypoint"]
diff --git a/day12/Makefile b/day12/Makefile
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+++ b/day12/Makefile
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+DAY = 12
+
+.PHONY: run clean push
+
+run: build
+	docker run -it --rm aoc2018day$(DAY)
+
+build: part* input
+	docker build -t aoc2018day$(DAY) .
+	touch build
+
+clean:
+	rm -f build
+
+push: build
+	docker tag aoc2018day$(DAY) advent.4574.co.uk/aoc2018day$(DAY)
+	docker push advent.4574.co.uk/aoc2018day$(DAY)
diff --git a/day12/entrypoint b/day12/entrypoint
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+++ b/day12/entrypoint
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+#!/bin/bash
+
+if [ -x part1 ] ; then
+	echo -ne "Part 1:\n\t"
+	time ./part1 < input
+fi
+if [ -x part1 -a -x part2 ] ; then
+	echo
+fi
+if [ -x part2 ] ; then
+	echo -ne "Part 2:\n\t"
+	time ./part2 < input
+fi
diff --git a/day12/input b/day12/input
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+++ b/day12/input
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+initial state: #....#.#....#....#######..##....###.##....##.#.#.##...##.##.#...#..###....#.#...##.###.##.###...#..#
+
+#..#. => #
+#...# => #
+.##.# => #
+#.... => .
+..#.. => .
+#.##. => .
+##... => #
+##.#. => #
+.#.## => #
+.#.#. => .
+###.. => .
+#..## => .
+###.# => .
+...## => .
+#.#.. => #
+..... => .
+##### => #
+..### => .
+..#.# => #
+....# => .
+...#. => #
+####. => #
+.#... => #
+#.#.# => #
+.##.. => #
+..##. => .
+##..# => .
+.#..# => #
+##.## => #
+.#### => .
+.###. => #
+#.### => .
diff --git a/day12/part1 b/day12/part1
new file mode 100755
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--- /dev/null
+++ b/day12/part1
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+#!/usr/bin/env ruby
+
+input = $stdin.readlines.map(&:strip)
+
+is = input[0].split(" ")[2]
+rs = input[2..-1]
+
+class Plants
+  def initialize(initial_state, rules)
+    @state = Hash.new(false)
+    parse_state_string(initial_state)
+    @rules = []
+    parse_rules_lines(rules)
+  end
+
+  def step(t = 1)
+    t.times do
+      newstate = Hash.new(false)
+
+      min = @state.keys.min
+      max = @state.keys.max
+      ((min-5)..(max+5)).each do |i|
+        res = false
+        @rules.each do |r|
+          ires = true
+          (-2..2).each do |o|
+            if @state[i + o] != r[o + 2] then
+              ires = false
+            end
+          end
+          if ires then
+            res = true
+          end
+        end
+        if res then
+          newstate[i] = true
+        end
+      end
+
+      @state = newstate
+    end
+  end
+
+  def sum
+    @state.select { |_, s| s }.keys.sum
+  end
+
+  private
+  def parse_state_string(state)
+    state.chars.each_with_index do |s, i|
+      @state[i] = s == "#"
+    end
+  end
+
+  def parse_rules_lines(rules)
+    rules.each do |rule|
+      c, r = rule.split(" => ")
+      if r == "#" then
+        @rules << c.chars.map { |p| p == "#" }
+      end
+    end
+  end
+end
+
+m = Plants.new(is, rs)
+
+m.step(20)
+
+puts m.sum
diff --git a/day12/part2 b/day12/part2
new file mode 100755
index 0000000..e1af0ed
--- /dev/null
+++ b/day12/part2
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+#!/usr/bin/env ruby
+
+input = $stdin.readlines.map(&:strip)
+
+is = input[0].split(" ")[2]
+rs = input[2..-1]
+
+class Plants
+  def initialize(initial_state, rules)
+    @state = Hash.new(false)
+    parse_state_string(initial_state)
+    @rules = []
+    parse_rules_lines(rules)
+  end
+
+  def step(t = 1)
+    t.times do
+      newstate = Hash.new(false)
+
+      min = @state.keys.min
+      max = @state.keys.max
+      ((min-5)..(max+5)).each do |i|
+        res = false
+        @rules.each do |r|
+          ires = true
+          (-2..2).each do |o|
+            if @state[i + o] != r[o + 2] then
+              ires = false
+            end
+          end
+          if ires then
+            res = true
+          end
+        end
+        if res then
+          newstate[i] = true
+        end
+      end
+
+      @state = newstate
+    end
+  end
+
+  def sum
+    @state.select { |_, s| s }.keys.sum
+  end
+
+  private
+  def parse_state_string(state)
+    state.chars.each_with_index do |s, i|
+      @state[i] = s == "#"
+    end
+  end
+
+  def parse_rules_lines(rules)
+    rules.each do |rule|
+      c, r = rule.split(" => ")
+      if r == "#" then
+        @rules << c.chars.map { |p| p == "#" }
+      end
+    end
+  end
+end
+
+m = Plants.new(is, rs)
+
+m.step(50000000000)
+
+puts m.sum