Day 06

3 files changed, 93 insertions, 0 deletions

diff --git a/day06/input b/day06/input
new file mode 100644
index 0000000..32e8d7e
--- /dev/null
+++ b/day06/input
@@ -0,0 +1 @@
+11	11	13	7	0	15	5	5	4	4	1	1	7	1	15	11
diff --git a/day06/part1 b/day06/part1
new file mode 100755
index 0000000..e615e84
--- /dev/null
+++ b/day06/part1
@@ -0,0 +1,47 @@
+#!/usr/bin/env ruby
+
+input = gets.chomp.split("\t").map(&:to_i)
+
+def index_of_max(arr)
+  idx = 0
+  max = 0
+
+  (0...arr.length).each do |i|
+    if arr[i] > max then
+      idx = i
+      max = arr[i]
+    end
+  end
+
+  return idx
+end
+
+def redistribute(arr, idx)
+  new = arr.dup
+  len = new.length
+
+  blks = new[idx]
+  new[idx] = 0
+
+  i = idx
+  while blks > 0 do
+    i = (i + 1) % len
+    new[i] += 1
+    blks -= 1
+  end
+
+  return new
+end
+
+previous = []
+state = input.dup
+steps = 0
+
+until previous.include?(state) do
+  newstate = redistribute(state, index_of_max(state))
+  previous << state
+  state = newstate
+  steps += 1
+end
+
+puts steps
diff --git a/day06/part2 b/day06/part2
new file mode 100755
index 0000000..9b8d8de
--- /dev/null
+++ b/day06/part2
@@ -0,0 +1,45 @@
+#!/usr/bin/env ruby
+
+input = gets.chomp.split("\t").map(&:to_i)
+
+def index_of_max(arr)
+  idx = 0
+  max = 0
+
+  (0...arr.length).each do |i|
+    if arr[i] > max then
+      idx = i
+      max = arr[i]
+    end
+  end
+
+  return idx
+end
+
+def redistribute(arr, idx)
+  new = arr.dup
+  len = new.length
+
+  blks = new[idx]
+  new[idx] = 0
+
+  i = idx
+  while blks > 0 do
+    i = (i + 1) % len
+    new[i] += 1
+    blks -= 1
+  end
+
+  return new
+end
+
+previous = []
+state = input.dup
+
+until previous.include?(state) do
+  newstate = redistribute(state, index_of_max(state))
+  previous << state
+  state = newstate
+end
+
+puts previous.length - previous.index(state)