Day Eight

2 files changed, 673 insertions, 0 deletions

diff --git a/2020/eight.nim b/2020/eight.nim
new file mode 100644
index 0000000..eec42ea
--- /dev/null
+++ b/2020/eight.nim
@@ -0,0 +1,40 @@
+# Day Eight: Handheld Halting
+import os, strutils, sequtils
+
+let input: string = paramStr(1)
+var program: seq[string] = split(strip(readFile(input)), '\n')
+
+proc execute(program: seq[string], executed: seq[int]) =
+  var executed = executed
+  var i, time, acc: int = 0
+  while i < len(program) and time < 250:
+    if executed[i] < 0:
+      echo acc
+      break
+    dec(executed[i])
+    var op: string = program[i][0..2]
+    var arg: int = parseInt(program[i][4..^1])
+    case op
+    of "acc":
+      inc(acc, arg)
+      inc(i)
+    of "jmp":
+      inc(i, arg)
+    of "nop":
+      inc(i)
+    else:
+      discard
+    inc(time)
+  if i >= len(program):
+    echo acc
+
+execute(program, repeat(0, len(program)))
+
+for i, instruction in program:
+  var program = program
+  program[i] =
+    if contains(instruction, "jmp"):
+      replace(instruction, "jmp", "nop")
+    else:
+      replace(instruction, "nop", "jmp")
+  execute(program, repeat(100, len(program)))
diff --git a/2020/input/eight.txt b/2020/input/eight.txt
new file mode 100644
index 0000000..2526508
--- /dev/null
+++ b/2020/input/eight.txt
@@ -0,0 +1,633 @@
+acc +37
+acc -1
+nop +512
+acc +0
+jmp +60
+acc -3
+nop +317
+jmp +130
+acc +22
+acc +34
+jmp +486
+acc -18
+nop +610
+acc -14
+nop +274
+jmp +439
+acc -6
+acc -1
+acc -4
+acc +7
+jmp +175
+nop +179
+jmp +197
+jmp +76
+acc -1
+acc +24
+jmp +472
+acc +8
+acc -15
+acc +0
+jmp +551
+acc +46
+acc +27
+jmp +1
+acc +45
+jmp +153
+acc +14
+jmp +207
+jmp +1
+jmp +557
+nop +424
+jmp +571
+nop -19
+nop +9
+acc +2
+acc +29
+jmp +14
+acc -10
+acc +43
+acc +43
+jmp +75
+jmp +311
+jmp +517
+acc -6
+acc +13
+jmp +140
+nop +348
+acc +0
+jmp +275
+jmp +52
+jmp +110
+acc +11
+acc +15
+jmp +13
+acc +7
+jmp +216
+jmp +174
+nop +24
+acc -16
+acc +46
+acc -17
+jmp +519
+acc -15
+acc +46
+acc -4
+jmp +309
+acc +14
+acc +36
+acc -15
+jmp +244
+acc +37
+acc +43
+jmp +146
+jmp +260
+jmp +217
+acc +39
+jmp +454
+nop +16
+nop +255
+acc +31
+jmp +13
+acc +38
+acc +45
+acc +24
+jmp +534
+acc +13
+acc +44
+acc +34
+jmp +286
+jmp +1
+acc -12
+jmp -45
+jmp +147
+acc -2
+acc +24
+nop +391
+acc +11
+jmp +242
+acc +1
+acc +28
+jmp +423
+acc +5
+jmp +319
+acc +45
+nop +350
+acc +34
+acc +7
+jmp +47
+nop +32
+acc +2
+acc +0
+jmp +252
+acc -4
+acc +23
+jmp +452
+acc -5
+acc +48
+jmp -104
+acc +38
+jmp +172
+acc +7
+acc +31
+jmp +5
+acc +19
+acc +12
+acc +26
+jmp +232
+acc -12
+nop +121
+nop +80
+acc +46
+jmp +126
+jmp +82
+nop +69
+jmp -128
+acc +18
+acc +45
+acc +14
+acc +45
+jmp +219
+jmp +422
+acc +2
+acc +40
+acc +13
+jmp +450
+acc +48
+jmp +172
+acc +19
+acc -10
+jmp +69
+nop +336
+nop -6
+jmp +265
+jmp -136
+jmp +350
+acc +31
+acc +39
+nop +389
+nop +404
+jmp +16
+acc +13
+nop -41
+acc -2
+acc -14
+jmp +159
+jmp -111
+acc +40
+acc +36
+acc -17
+jmp -143
+acc +36
+acc +29
+acc +19
+acc +0
+jmp +159
+jmp +279
+acc +31
+jmp +346
+acc +15
+nop +173
+acc +48
+jmp -183
+acc +16
+acc +31
+jmp +418
+acc -13
+jmp +280
+acc +30
+nop +229
+jmp -139
+acc +0
+acc +9
+jmp +354
+acc +12
+jmp +310
+jmp -129
+acc -8
+jmp -96
+acc -3
+acc +1
+jmp +51
+jmp +303
+acc +28
+jmp -186
+acc +36
+acc -10
+nop +72
+nop +345
+jmp +200
+acc +6
+acc -14
+jmp +87
+nop +318
+jmp +273
+nop +309
+acc +50
+jmp +147
+jmp +387
+acc +38
+nop -169
+acc +44
+jmp +28
+nop +208
+nop +43
+acc +26
+acc -13
+jmp -160
+jmp +233
+acc +22
+jmp +357
+jmp +374
+acc -6
+acc +38
+jmp +100
+jmp -36
+acc +38
+nop +330
+acc +46
+jmp -43
+acc +34
+nop +239
+acc +45
+acc +15
+jmp +48
+acc +49
+acc +20
+acc -5
+acc +41
+jmp +70
+jmp +211
+jmp +144
+acc +29
+acc +36
+acc -15
+jmp -24
+jmp +1
+jmp -17
+acc -18
+acc +27
+acc +34
+jmp -21
+jmp +1
+acc +35
+acc -5
+acc +24
+jmp +337
+nop -240
+jmp +180
+acc -1
+nop +49
+jmp +260
+acc +40
+acc +42
+jmp -165
+acc +31
+acc +30
+nop -234
+jmp +27
+acc +45
+acc +48
+acc +44
+acc -19
+jmp +70
+acc +20
+acc +18
+jmp +219
+acc +46
+jmp -85
+acc +43
+acc +21
+jmp -4
+acc +37
+acc +26
+acc +16
+jmp -257
+acc +39
+acc +7
+jmp -260
+acc +42
+acc +10
+acc +36
+acc +47
+jmp +2
+jmp -249
+acc +20
+acc -1
+acc +21
+jmp +74
+jmp +31
+acc +32
+jmp +64
+acc +34
+jmp -255
+acc -8
+acc -2
+acc +26
+jmp -102
+jmp +229
+acc -14
+acc +25
+jmp -154
+acc -15
+jmp -92
+nop -37
+acc -5
+acc +50
+acc +43
+jmp +73
+acc +1
+acc -17
+acc +19
+acc +24
+jmp -319
+nop -225
+jmp -304
+acc +49
+acc +5
+acc -17
+jmp +14
+acc +42
+acc -9
+acc -10
+acc +45
+jmp -125
+jmp -46
+acc +13
+acc +11
+nop +199
+acc -19
+jmp -159
+acc +1
+jmp +253
+acc +7
+jmp +233
+nop -76
+acc +31
+acc +44
+jmp -18
+acc +47
+nop +227
+jmp +178
+nop -22
+jmp -44
+jmp +24
+nop +122
+acc +20
+acc +43
+jmp -81
+acc -15
+acc +10
+acc +40
+jmp +108
+acc +45
+jmp +35
+acc +44
+jmp +36
+nop -2
+nop -320
+jmp +1
+acc +47
+jmp -6
+acc -16
+acc +49
+nop +56
+jmp +104
+acc +40
+jmp -159
+acc +30
+jmp +56
+acc +47
+acc -6
+acc +47
+acc +2
+jmp -102
+acc +45
+jmp -262
+acc +36
+acc +42
+acc -17
+jmp -90
+acc +18
+nop +7
+acc -14
+jmp -194
+acc +16
+acc +31
+acc +26
+jmp -257
+acc +25
+jmp -367
+jmp +69
+nop -102
+acc +47
+jmp -356
+nop -105
+acc +6
+jmp -42
+acc +40
+jmp -368
+acc +42
+jmp +84
+acc +17
+acc +14
+acc -17
+acc -14
+jmp -80
+acc +42
+acc +11
+acc -14
+jmp -77
+acc -12
+acc +8
+acc -19
+jmp -206
+acc +6
+acc +18
+nop +94
+acc -2
+jmp -330
+acc -15
+jmp -367
+acc -15
+acc +40
+jmp +143
+jmp -178
+acc -1
+jmp +140
+acc +13
+acc +47
+jmp -271
+acc +29
+nop -30
+nop -344
+jmp -251
+jmp +98
+acc +45
+acc -17
+acc +5
+jmp +1
+jmp -299
+acc +34
+acc +7
+acc +7
+nop +16
+jmp -106
+jmp -399
+jmp -291
+acc -4
+acc +26
+jmp -376
+nop -444
+nop +59
+acc +27
+nop +89
+jmp -188
+acc +21
+nop -246
+acc +6
+jmp -24
+acc +35
+jmp +1
+jmp -361
+acc +48
+acc -5
+acc +19
+jmp +74
+jmp -56
+jmp +43
+acc +50
+nop -275
+acc +39
+acc -11
+jmp -258
+acc +8
+jmp -190
+acc +46
+jmp +1
+nop -188
+acc -15
+jmp +12
+nop -5
+nop -444
+acc +0
+jmp -129
+acc -11
+acc +28
+jmp -452
+acc -4
+acc +24
+nop -176
+jmp -56
+acc +47
+acc +33
+jmp -432
+jmp -19
+acc +32
+jmp +1
+acc +7
+nop -179
+jmp -49
+nop -66
+acc +20
+jmp -122
+acc +1
+acc +10
+acc +16
+jmp +40
+acc +11
+acc +6
+jmp -454
+acc -2
+acc +12
+nop -228
+jmp -165
+acc +42
+nop -212
+acc +49
+jmp -286
+acc +42
+acc +24
+acc +38
+jmp -440
+acc +29
+acc +8
+acc +21
+jmp -288
+acc +2
+jmp -427
+acc +17
+acc +45
+acc +33
+jmp -333
+acc +6
+jmp -445
+nop -283
+acc -18
+jmp +1
+jmp +1
+jmp -492
+jmp +53
+acc +26
+jmp -107
+nop -377
+jmp -155
+acc +22
+jmp -523
+jmp -127
+acc +2
+nop -168
+acc +15
+jmp -343
+acc +34
+acc +0
+acc +0
+jmp -241
+acc +30
+acc +40
+acc +46
+acc -11
+jmp -216
+acc +31
+jmp -86
+acc +34
+acc -15
+nop -4
+jmp -74
+acc -1
+acc +13
+acc -2
+jmp -119
+acc +21
+nop -516
+acc +24
+jmp -580
+nop -200
+acc +18
+jmp -318
+acc +0
+nop -483
+acc +15
+acc -9
+jmp -30
+jmp -462
+jmp -476
+acc +18
+acc -14
+jmp -91
+acc -6
+acc +32
+nop -611
+acc +8
+jmp -613
+acc +23
+acc +7
+acc +30
+acc +48
+jmp -222
+jmp -326
+acc +46
+nop -108
+acc +17
+acc -16
+jmp +1