From 65a847f1d68d8902e3a3b1b39541fa97ff44a53b Mon Sep 17 00:00:00 2001
From: Jan-Lukas Else <mail@jlelse.de>
Date: Tue, 8 Dec 2020 08:16:22 +0100
Subject: [PATCH] Day 8

---
 8/input.txt | 601 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 8/main.go   |  90 ++++++++
 2 files changed, 691 insertions(+)
 create mode 100644 8/input.txt
 create mode 100644 8/main.go

diff --git a/8/input.txt b/8/input.txt
new file mode 100644
index 0000000..038c164
--- /dev/null
+++ b/8/input.txt
@@ -0,0 +1,601 @@
+acc +22
+acc +34
+jmp +167
+acc +46
+acc +25
+acc -10
+acc +11
+jmp +540
+acc +0
+jmp +242
+acc +26
+acc +46
+jmp +242
+jmp +287
+acc -8
+acc +30
+acc +3
+nop +350
+jmp +471
+acc +2
+acc +0
+acc +14
+jmp +207
+jmp +1
+acc -10
+acc +12
+jmp +281
+acc +18
+jmp +515
+acc -18
+acc +33
+jmp +379
+acc +48
+acc +38
+jmp +220
+acc +44
+nop +546
+acc +21
+jmp +537
+acc +33
+nop +224
+nop +379
+jmp +2
+jmp -30
+jmp +246
+acc -14
+acc -3
+jmp +410
+acc +50
+nop +323
+acc +2
+acc +24
+jmp +25
+jmp +372
+acc +29
+acc +15
+nop +34
+jmp +531
+acc +48
+acc -3
+acc -18
+acc -13
+jmp -30
+acc +7
+jmp +444
+acc +47
+jmp -3
+jmp +1
+nop +514
+jmp +39
+jmp +434
+acc +0
+acc +11
+acc +12
+acc -17
+jmp +142
+jmp +367
+acc -18
+nop +69
+acc -12
+jmp +16
+jmp +39
+nop +486
+acc +16
+jmp +1
+jmp -72
+jmp +1
+jmp +1
+nop +355
+jmp -7
+acc +1
+acc -12
+acc +12
+jmp +131
+acc +35
+jmp +74
+acc +9
+acc +26
+acc -14
+jmp -60
+acc +20
+acc +40
+acc +22
+acc +24
+jmp +209
+acc +43
+jmp +347
+jmp +346
+acc +0
+jmp +348
+acc +18
+jmp -79
+acc -11
+acc -16
+acc +7
+jmp +192
+acc +40
+acc +20
+nop -6
+jmp -7
+acc -18
+jmp +395
+nop +219
+acc -18
+jmp -53
+acc +22
+nop -1
+nop +29
+jmp +468
+acc +42
+acc +7
+acc +3
+acc +46
+jmp -8
+acc +29
+acc -18
+acc +17
+acc +41
+jmp +272
+jmp +222
+acc -10
+acc +32
+acc -14
+jmp -38
+acc +49
+acc +40
+jmp +97
+nop +375
+acc +19
+acc +45
+jmp -45
+jmp +195
+acc +19
+jmp +330
+acc +38
+jmp +7
+acc +40
+nop +150
+acc +19
+jmp +406
+acc +9
+jmp -49
+acc -3
+jmp +176
+acc +2
+nop +20
+acc +25
+nop +349
+jmp -129
+acc +27
+nop +301
+acc +37
+jmp +271
+acc +3
+acc +10
+acc +26
+acc +49
+jmp +58
+nop +151
+jmp +72
+acc -1
+acc +32
+acc -11
+acc -7
+jmp +155
+jmp +1
+acc +44
+acc +2
+jmp -140
+acc +13
+acc +46
+acc -3
+jmp -58
+jmp +174
+acc +0
+acc -18
+acc +25
+jmp -178
+acc -19
+acc +37
+acc +0
+acc +49
+jmp +366
+acc +17
+acc +9
+acc +25
+jmp -37
+jmp +328
+acc +50
+jmp +81
+acc +1
+acc +43
+acc +30
+jmp +80
+acc +17
+acc +43
+jmp +234
+acc +43
+nop +271
+acc -11
+jmp +331
+nop +335
+acc +43
+jmp -160
+acc +27
+acc +34
+jmp -74
+nop +73
+jmp -11
+acc -18
+jmp -118
+acc +23
+acc +19
+nop -108
+jmp +73
+acc +25
+acc -19
+acc +23
+acc -7
+jmp -77
+acc +0
+acc +1
+jmp +233
+jmp +1
+jmp +1
+acc +7
+jmp +248
+acc +0
+acc -17
+acc +19
+jmp -15
+acc +10
+jmp +273
+jmp +88
+acc +40
+acc +35
+jmp +1
+acc +38
+jmp +241
+acc -2
+acc +36
+acc -1
+acc +18
+jmp +78
+nop +58
+acc -9
+acc +38
+acc +44
+jmp +307
+acc +10
+acc +30
+jmp -163
+acc -16
+acc +29
+acc -19
+jmp -185
+jmp +167
+nop +52
+jmp -251
+acc +31
+acc -14
+jmp +186
+nop +1
+acc +42
+acc +9
+jmp -160
+acc +10
+acc +43
+acc +14
+jmp -177
+acc -16
+jmp +265
+jmp -158
+acc -15
+jmp +152
+acc +22
+acc +1
+acc +40
+jmp +1
+jmp +252
+acc -19
+acc -1
+jmp -109
+acc +11
+acc -3
+acc +8
+jmp +16
+acc +39
+acc +12
+acc +24
+jmp -154
+acc +6
+jmp -156
+jmp +119
+acc +18
+jmp +1
+jmp -44
+acc -13
+jmp +79
+acc +9
+nop +262
+jmp +56
+nop +50
+acc -4
+acc +36
+acc +12
+jmp -54
+acc -2
+jmp -77
+acc +11
+acc +3
+acc +38
+jmp -185
+acc +28
+jmp -44
+jmp +54
+acc +39
+nop +18
+jmp -84
+jmp +132
+jmp -301
+acc +12
+jmp -334
+acc -19
+acc -10
+jmp -55
+acc +24
+acc +40
+acc -18
+jmp +212
+jmp +70
+acc -4
+nop +173
+jmp +67
+jmp +66
+acc +44
+acc +8
+jmp +236
+acc +47
+acc +29
+jmp -21
+jmp +143
+acc +22
+acc +37
+acc +37
+acc +25
+jmp -339
+jmp +1
+nop +200
+acc +25
+jmp +208
+jmp +93
+acc -1
+acc -13
+acc +30
+jmp -321
+jmp -268
+acc +14
+jmp -311
+acc +1
+acc +20
+acc +41
+jmp -128
+jmp -173
+acc -10
+acc +41
+acc +25
+acc +38
+jmp +137
+nop -99
+acc +47
+acc -3
+acc -9
+jmp -259
+acc +0
+acc +40
+jmp +126
+acc +48
+acc -4
+acc +23
+jmp -136
+nop +103
+acc +27
+jmp -149
+acc +39
+jmp -323
+acc -13
+jmp +1
+nop -79
+jmp -342
+acc +36
+nop +9
+acc -15
+acc -19
+jmp -216
+acc +27
+acc -17
+nop +72
+acc +3
+jmp -142
+jmp -357
+acc +39
+acc -18
+acc -2
+jmp -361
+acc +26
+acc -15
+acc +21
+jmp +1
+jmp +21
+nop +20
+jmp +77
+acc +36
+acc +6
+acc +32
+jmp -295
+jmp +63
+acc -15
+nop -371
+jmp -196
+acc +27
+acc +36
+jmp -152
+acc +43
+jmp +149
+jmp +85
+nop -57
+acc +8
+jmp -241
+jmp -206
+acc +5
+jmp -282
+jmp -344
+acc +24
+acc +12
+jmp -138
+jmp -31
+acc +4
+acc +27
+jmp -224
+acc +16
+acc +42
+acc +24
+jmp -316
+acc +41
+jmp +10
+jmp -403
+jmp -90
+nop -79
+acc +2
+jmp +19
+acc +42
+acc +12
+jmp -9
+jmp +104
+acc -9
+acc -11
+jmp -299
+acc +19
+acc +7
+acc -11
+acc -7
+jmp -335
+acc +24
+jmp -80
+acc +45
+acc +39
+acc +18
+jmp -348
+acc +5
+acc -5
+jmp -94
+acc +35
+jmp -221
+acc -3
+jmp -112
+acc +10
+acc +23
+jmp +18
+nop -53
+jmp -315
+acc +12
+acc +19
+jmp -426
+jmp -175
+acc +40
+acc +25
+jmp +23
+nop -14
+nop +79
+acc +21
+jmp -301
+acc +22
+acc -10
+jmp +1
+jmp +15
+acc +27
+jmp -409
+acc +45
+nop -341
+acc +22
+jmp -89
+jmp +60
+acc +11
+jmp -461
+acc +39
+acc -11
+acc +10
+jmp -173
+jmp -447
+nop +38
+acc +5
+jmp -65
+acc +45
+jmp -217
+acc +1
+acc -7
+nop -460
+acc +45
+jmp -468
+nop -477
+acc +0
+jmp -270
+jmp -230
+acc +36
+acc +21
+jmp -21
+jmp -225
+acc -11
+jmp +1
+jmp -511
+jmp -4
+acc -5
+acc -4
+acc -15
+jmp -204
+jmp -62
+acc +50
+acc +34
+acc +32
+jmp -489
+nop -108
+jmp -125
+acc -2
+jmp -187
+nop +1
+jmp -284
+jmp -285
+acc +43
+acc -1
+jmp -293
+nop -49
+acc -14
+acc +25
+jmp -233
+nop -53
+jmp -456
+jmp -226
+acc +39
+jmp -244
+acc +16
+jmp -82
+acc +17
+acc +47
+acc +16
+jmp -244
+nop -87
+jmp -150
+jmp -99
+jmp +1
+acc -9
+acc +48
+jmp -515
+acc -1
+jmp -546
+jmp -191
+acc -16
+acc +27
+nop -369
+acc -7
+jmp +1
\ No newline at end of file
diff --git a/8/main.go b/8/main.go
new file mode 100644
index 0000000..797a3a4
--- /dev/null
+++ b/8/main.go
@@ -0,0 +1,90 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"regexp"
+	"strconv"
+)
+
+type instruction struct {
+	op       string
+	arg      int
+	executed bool
+}
+
+func main() {
+	instructionRe := regexp.MustCompile(`^(?P<op>\w+) (?P<arg>[\+\-]\d+)$`)
+	parsedInstructions := []instruction{}
+
+	file, _ := os.Open("input.txt")
+	defer file.Close()
+	for scanner := bufio.NewScanner(file); scanner.Scan(); {
+		text := scanner.Text()
+		arg, _ := strconv.Atoi(instructionRe.ReplaceAllString(text, "$arg"))
+		parsedInstructions = append(parsedInstructions, instruction{instructionRe.ReplaceAllString(text, "$op"), arg, false})
+	}
+
+	makeInstructions := func() []instruction {
+		instructions := make([]instruction, len(parsedInstructions))
+		copy(instructions, parsedInstructions)
+		return instructions
+	}
+
+	var accumulator, pos int
+
+	for newInstructions := makeInstructions(); true; {
+		instr := &newInstructions[pos]
+		if instr.executed {
+			break
+		}
+		switch instr.op {
+		case "acc":
+			accumulator += instr.arg
+			pos++
+		case "nop":
+			pos++
+		case "jmp":
+			pos += instr.arg
+		}
+		instr.executed = true
+	}
+
+	fmt.Println("Part 1:", accumulator)
+
+modifyOpLoop:
+	for lastModifiedOp := 0; true; lastModifiedOp++ {
+		newInstructions := makeInstructions()
+		if instr := &newInstructions[lastModifiedOp]; instr.op == "jmp" {
+			instr.op = "nop"
+		} else if instr.op == "nop" {
+			instr.op = "jmp"
+		} else {
+			continue
+		}
+		accumulator = 0
+		pos = 0
+		for {
+			if pos >= len(newInstructions) {
+				break modifyOpLoop
+			}
+			instr := &newInstructions[pos]
+			if instr.executed {
+				break
+			}
+			switch instr.op {
+			case "acc":
+				accumulator += instr.arg
+				pos++
+			case "nop":
+				pos++
+			case "jmp":
+				pos += instr.arg
+			}
+			instr.executed = true
+		}
+	}
+
+	fmt.Println("Part 2:", accumulator)
+}