From 9a5568d1cf4535a48a878518bc9bf5550f728158 Mon Sep 17 00:00:00 2001
From: Jeremy Kaplan <jdkaplan@metagram.net>
Date: Mon, 7 Dec 2020 21:19:21 -0800
Subject: [PATCH] Day 8 Part 1

---
 2020/day8/day8.ex |  40 +++
 2020/day8/input   | 638 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 678 insertions(+)
 create mode 100644 2020/day8/day8.ex
 create mode 100644 2020/day8/input

diff --git a/2020/day8/day8.ex b/2020/day8/day8.ex
new file mode 100644
index 0000000..ab9e701
--- /dev/null
+++ b/2020/day8/day8.ex
@@ -0,0 +1,40 @@
+defmodule Day8 do
+  defp read_input do
+    Path.expand('input', Path.dirname(__ENV__.file))
+    |> File.read!()
+  end
+
+  defp parse_program(text) do
+    String.split(String.trim(text), "\n")
+    |> Enum.map(fn line ->
+      [op, val] = String.split(line)
+      {op, String.to_integer(val)}
+    end)
+  end
+
+  defp tick(program, pc, acc) do
+    case Enum.at(program, pc) do
+      {"nop", _} -> {pc + 1, acc}
+      {"acc", int} -> {pc + 1, acc + int}
+      {"jmp", int} -> {pc + int, acc}
+    end
+  end
+
+  defp find_loop(program, pc, acc, history) do
+    {next_pc, next_acc} = tick(program, pc, acc)
+    count = Map.get(history, next_pc, 0)
+
+    if count > 0 do
+      acc
+    else
+      find_loop(program, next_pc, next_acc, Map.put(history, next_pc, count + 1))
+    end
+  end
+
+  def part1 do
+    program = parse_program(read_input())
+    find_loop(program, 0, 0, %{})
+  end
+end
+
+Day8.part1() |> IO.inspect()
diff --git a/2020/day8/input b/2020/day8/input
new file mode 100644
index 0000000..63b0ff3
--- /dev/null
+++ b/2020/day8/input
@@ -0,0 +1,638 @@
+acc +48
+acc -15
+jmp +510
+acc -16
+acc -9
+acc +10
+acc +45
+jmp +76
+acc +43
+acc -5
+acc +1
+jmp +306
+jmp +265
+jmp +506
+nop +48
+nop +596
+jmp +212
+acc +30
+jmp +311
+jmp +592
+acc +10
+jmp +1
+jmp +153
+acc +13
+nop +282
+jmp +482
+acc -12
+acc +22
+jmp +294
+acc -14
+acc +13
+nop +471
+acc +26
+jmp -13
+acc +11
+acc +23
+acc +9
+jmp +1
+jmp +158
+acc +20
+acc -3
+jmp +69
+jmp +546
+acc +14
+acc +25
+nop +488
+jmp +502
+acc +14
+acc -11
+acc +25
+acc +0
+jmp +527
+acc +45
+acc +35
+acc +2
+acc +33
+jmp +522
+acc +44
+acc +18
+acc +30
+jmp +429
+jmp +290
+jmp +36
+acc +36
+jmp +366
+acc +0
+acc +39
+acc -16
+jmp +160
+jmp -27
+acc -4
+acc -3
+acc +24
+acc +11
+jmp +321
+jmp +86
+acc +24
+jmp +113
+acc +28
+nop +73
+jmp +47
+jmp +165
+jmp +198
+acc -19
+acc -13
+jmp +297
+nop +175
+nop +328
+jmp +16
+acc -16
+acc -17
+acc -7
+acc +38
+jmp +409
+acc +27
+acc +38
+acc +2
+jmp -63
+jmp +145
+acc +18
+nop -74
+acc +39
+acc -13
+jmp -69
+acc +40
+acc +47
+jmp +16
+acc +9
+acc +13
+jmp +494
+acc +34
+acc +7
+jmp +303
+acc +0
+jmp +474
+acc +33
+acc +41
+acc +25
+acc +31
+jmp -49
+acc -17
+jmp +54
+jmp +172
+acc +30
+acc -13
+acc +13
+jmp +236
+acc +19
+jmp +15
+acc +24
+acc -17
+jmp +7
+acc +40
+acc -7
+acc -13
+jmp -59
+acc -2
+jmp +118
+acc +50
+acc +10
+acc +43
+jmp +41
+jmp +406
+nop +163
+acc +26
+acc +34
+jmp +426
+acc +0
+acc +18
+acc +0
+acc +1
+jmp -117
+acc +42
+jmp +51
+acc +21
+jmp +378
+jmp -73
+jmp +437
+jmp +475
+acc -10
+jmp +418
+jmp +211
+acc +15
+acc +27
+acc +32
+acc +9
+jmp +151
+acc -15
+acc +6
+jmp -88
+acc +14
+acc +15
+jmp +1
+acc +47
+jmp -36
+acc +42
+acc +34
+nop -39
+jmp +329
+acc +24
+acc +3
+jmp +418
+acc +10
+acc -19
+acc +23
+jmp +1
+jmp +326
+nop -49
+acc +19
+jmp +323
+jmp -182
+acc +14
+nop +164
+acc +47
+acc -8
+jmp +111
+acc +10
+nop +240
+acc +21
+jmp +100
+acc +19
+acc +32
+acc -5
+jmp +396
+acc -14
+acc -13
+jmp +18
+nop -11
+acc +40
+acc +27
+jmp +1
+jmp -7
+acc -8
+acc +14
+acc +29
+acc +22
+jmp +146
+nop +355
+jmp +322
+acc +3
+acc +17
+jmp +1
+jmp +258
+jmp +404
+acc -3
+acc +36
+jmp +204
+jmp -3
+acc -11
+acc +11
+jmp +310
+jmp +1
+jmp +308
+acc +11
+jmp +1
+acc +47
+acc -14
+jmp -81
+acc -16
+jmp +1
+acc +28
+acc +32
+jmp +157
+acc -13
+jmp +21
+jmp +312
+jmp +121
+jmp +135
+nop -5
+nop +6
+acc +23
+jmp -136
+acc +10
+acc +7
+jmp +63
+acc +25
+nop -214
+jmp +42
+acc +12
+acc +2
+jmp +1
+acc +16
+acc +47
+jmp -246
+jmp +42
+acc +10
+acc +11
+nop +344
+nop +197
+jmp +190
+jmp +201
+jmp -167
+acc +38
+nop -45
+acc +37
+acc +12
+jmp +1
+jmp -235
+acc +9
+jmp +254
+acc +33
+acc +11
+nop -11
+jmp -131
+nop +22
+acc +29
+jmp +1
+jmp +30
+jmp -121
+acc -8
+nop -115
+acc -16
+acc +15
+jmp +98
+acc +39
+jmp +53
+acc +0
+acc +5
+jmp +139
+acc -12
+acc -13
+jmp +50
+acc +47
+acc -18
+acc +8
+jmp -243
+acc +22
+jmp +188
+acc +5
+acc +46
+acc +25
+jmp +277
+acc -12
+jmp +250
+nop +116
+acc -19
+jmp -178
+acc -3
+acc +21
+nop -163
+jmp -77
+jmp -15
+acc -8
+acc -11
+jmp +129
+acc +32
+acc +46
+nop +88
+jmp -51
+jmp +27
+acc -11
+nop +116
+acc +31
+jmp -4
+acc +41
+jmp -315
+acc +10
+nop -76
+acc +25
+nop -127
+jmp -298
+acc +20
+acc +1
+acc -19
+jmp -125
+acc +9
+acc +40
+jmp +133
+nop -250
+jmp -116
+jmp -189
+acc +50
+jmp +78
+acc -3
+acc +37
+jmp -131
+nop -336
+acc +22
+acc +37
+jmp +94
+acc +43
+jmp -319
+jmp -328
+acc -18
+acc +0
+acc +33
+jmp -4
+acc +16
+jmp +213
+acc -12
+acc +23
+jmp -175
+acc -17
+acc -12
+nop -141
+nop +228
+jmp -244
+acc +11
+acc +12
+nop +220
+nop -184
+jmp +236
+acc +42
+acc +0
+acc +45
+acc +34
+jmp +213
+acc -18
+acc +18
+nop +26
+jmp +150
+nop -293
+nop -277
+jmp -380
+jmp -133
+acc -13
+jmp -108
+acc +39
+jmp +223
+acc +47
+acc +14
+acc +10
+jmp -90
+acc -19
+nop -387
+acc +24
+acc -19
+jmp -203
+acc +4
+jmp -132
+acc +31
+nop -255
+nop +187
+nop +40
+jmp +126
+acc -19
+acc -1
+acc -13
+jmp -147
+acc +0
+jmp -363
+acc -5
+acc -11
+acc +31
+acc +44
+jmp -177
+nop -406
+acc +29
+acc +34
+jmp -174
+acc +8
+acc -6
+nop -367
+acc -8
+jmp +183
+nop -147
+jmp +104
+acc -8
+nop +69
+acc -10
+acc -8
+jmp -384
+acc +20
+acc +39
+acc -16
+acc +2
+jmp -303
+acc -13
+jmp +100
+acc +14
+acc +22
+acc +27
+jmp -354
+acc +1
+acc +39
+acc -7
+jmp -346
+acc -10
+jmp -450
+nop -188
+jmp +5
+jmp +1
+nop -381
+acc +42
+jmp -102
+acc +13
+acc +11
+nop -224
+jmp -213
+acc +46
+jmp +57
+nop +140
+jmp +131
+acc +30
+acc +25
+acc -10
+acc -13
+jmp -78
+jmp -144
+jmp -185
+acc -17
+acc +36
+acc +38
+jmp +144
+nop -4
+acc +9
+acc +17
+acc +19
+jmp +90
+acc +11
+nop -380
+acc +17
+jmp -403
+acc -2
+jmp +94
+acc +32
+acc +45
+nop -249
+jmp -27
+acc +13
+nop -5
+jmp -439
+acc +32
+acc +5
+jmp -478
+acc +43
+jmp -98
+acc -18
+jmp -100
+acc +14
+acc -14
+jmp -329
+acc +46
+acc +5
+jmp -353
+acc -3
+acc +29
+acc +44
+jmp -88
+acc -11
+acc -14
+jmp -100
+nop -441
+acc +2
+acc +25
+acc +4
+jmp +7
+acc -17
+jmp +1
+nop -296
+acc +4
+jmp -132
+jmp -417
+nop -287
+acc +48
+nop -40
+acc -4
+jmp -146
+nop -521
+jmp -183
+acc -13
+acc +22
+jmp +15
+acc +21
+acc +22
+acc +27
+acc +34
+jmp -35
+acc -13
+nop -417
+acc +40
+jmp -114
+acc +4
+acc +20
+acc -1
+acc -9
+jmp -514
+acc +8
+acc -17
+acc +19
+jmp -130
+acc +11
+jmp -250
+nop +58
+acc +36
+acc -3
+acc -5
+jmp -120
+acc +11
+acc +50
+acc -18
+jmp -419
+jmp +1
+nop -446
+acc +22
+acc +28
+jmp -43
+jmp -289
+acc +1
+jmp -421
+jmp +14
+nop -62
+jmp -55
+jmp +1
+acc +5
+acc +26
+acc +0
+jmp -477
+acc +35
+acc -17
+acc +21
+jmp -200
+acc -2
+jmp -128
+jmp -253
+acc +28
+acc +47
+acc +27
+jmp -118
+acc +33
+jmp -228
+acc +41
+jmp -45
+acc +11
+acc -14
+jmp +1
+acc +35
+jmp -118
+acc +13
+acc +37
+jmp -108
+acc +44
+nop -523
+acc +45
+acc +39
+jmp +6
+jmp -582
+jmp -139
+acc -3
+jmp +1
+jmp -9
+acc +36
+acc +3
+acc +49
+jmp -562
+acc +14
+jmp -422
+acc +41
+acc +35
+jmp -582
+acc -11
+acc +0
+jmp -291
+acc -5
+acc -6
+acc +31
+acc -11
+jmp +1