Implementation day 8

2020/inputs/08.txt

@@ -0,0 +1,612 @@
+acc +18
+nop +222
+acc -16
+acc +28
+jmp +475
+acc -6
+jmp +584
+acc -12
+acc -8
+jmp +554
+acc -9
+acc +12
+acc -16
+acc +27
+jmp +336
+acc -4
+jmp +214
+acc +38
+jmp +61
+acc +3
+acc +28
+acc +5
+acc -19
+jmp +584
+nop +206
+jmp +506
+acc +36
+jmp +133
+acc +20
+acc +43
+acc -18
+jmp +409
+acc +24
+jmp +131
+acc -12
+acc +7
+acc +7
+jmp +454
+acc +37
+acc -6
+nop +558
+acc +31
+jmp +124
+acc -15
+nop +201
+acc -7
+jmp +297
+acc +3
+nop +517
+jmp +221
+jmp +211
+acc +28
+acc +35
+jmp +5
+acc +31
+nop +325
+acc -15
+jmp +116
+jmp +1
+nop +333
+acc -2
+acc -5
+jmp +138
+acc +19
+acc +9
+jmp +180
+acc +18
+jmp +228
+jmp +495
+jmp +382
+acc +20
+nop +414
+nop +139
+acc +33
+jmp +171
+acc -10
+jmp +41
+acc -2
+jmp +80
+acc +20
+nop +451
+acc +2
+acc +24
+jmp +102
+acc +1
+acc -11
+acc +9
+acc +38
+jmp -73
+acc +17
+acc +16
+acc +12
+acc +43
+jmp +168
+jmp +286
+acc +6
+acc +6
+jmp +271
+acc -17
+acc -5
+acc +1
+jmp -50
+acc -9
+acc +6
+acc -2
+acc +33
+jmp +385
+acc +18
+acc +24
+jmp +370
+acc -5
+acc +23
+acc +6
+jmp +98
+acc -10
+acc -16
+jmp +329
+nop +41
+jmp +463
+nop +224
+acc +35
+jmp +345
+acc +34
+acc -18
+acc +5
+jmp +177
+nop -57
+nop -80
+acc +20
+jmp -12
+acc +24
+acc +39
+jmp +363
+jmp +253
+acc -14
+acc +0
+acc +22
+jmp +118
+acc +43
+acc -2
+jmp +300
+acc -14
+acc +8
+acc +47
+jmp +271
+jmp +420
+acc +33
+acc +15
+acc +20
+acc +25
+jmp +84
+acc +41
+jmp +420
+acc +25
+jmp +238
+jmp +1
+acc +14
+jmp +415
+jmp +68
+jmp +262
+acc +34
+jmp +346
+acc +39
+jmp +56
+jmp +364
+jmp -133
+acc +13
+jmp +1
+acc +33
+jmp +408
+acc +29
+acc -4
+jmp +319
+jmp +106
+jmp +228
+acc -8
+acc +8
+acc +22
+jmp -146
+jmp +223
+acc +27
+nop +191
+acc +49
+jmp +331
+jmp +39
+jmp -170
+acc +28
+acc -6
+acc +50
+jmp +268
+acc +41
+nop +254
+acc +28
+jmp +269
+jmp +140
+acc +10
+nop +131
+acc +3
+jmp -40
+jmp +373
+acc +47
+jmp -91
+acc -19
+jmp +300
+acc -2
+jmp +1
+acc +44
+acc -11
+jmp +306
+acc +33
+jmp -15
+acc +9
+jmp +1
+jmp +144
+acc +40
+nop +184
+nop -75
+nop +228
+jmp +296
+acc +22
+nop +364
+jmp -214
+jmp +18
+jmp +375
+acc +22
+jmp -67
+acc +8
+acc -17
+jmp +174
+jmp -99
+nop -45
+acc +7
+jmp -213
+jmp -218
+acc +50
+nop +52
+nop +98
+jmp -142
+acc +18
+jmp +252
+acc +36
+jmp -194
+acc +1
+nop -53
+jmp -127
+jmp +327
+acc +7
+acc -9
+acc +39
+nop -127
+jmp +84
+jmp -117
+nop -29
+acc +43
+jmp -216
+acc +25
+acc +16
+acc +40
+nop +122
+jmp +140
+jmp +180
+acc +42
+acc -5
+acc -14
+jmp -84
+jmp -31
+acc +37
+acc -11
+jmp -217
+jmp +210
+jmp +170
+nop +301
+jmp +309
+acc +6
+jmp +135
+acc +6
+nop -123
+acc +17
+jmp +315
+acc -1
+nop -46
+nop -58
+nop -59
+jmp +202
+acc +48
+acc +38
+jmp +86
+acc -4
+acc +33
+acc +28
+jmp -50
+nop +43
+acc +38
+acc +13
+jmp +33
+acc +4
+acc +6
+jmp -78
+acc +22
+acc +7
+acc -9
+jmp -56
+acc +30
+nop +54
+nop -81
+nop +198
+jmp +252
+jmp +1
+acc +6
+acc -10
+acc +29
+jmp -242
+jmp +1
+acc +42
+acc +34
+acc +22
+jmp +231
+acc +29
+acc -10
+jmp -161
+acc +37
+acc +9
+jmp -77
+acc -15
+acc +32
+acc +32
+jmp -6
+acc +0
+nop -124
+nop +174
+jmp +20
+acc +45
+acc +24
+jmp -13
+acc +6
+acc -10
+acc +23
+acc -15
+jmp +34
+acc +5
+acc +38
+acc +42
+jmp -116
+acc +0
+acc +8
+jmp -243
+acc -18
+acc +25
+acc +1
+jmp +158
+nop +65
+jmp +1
+jmp +151
+acc +12
+acc +12
+jmp +1
+jmp -305
+jmp +29
+jmp -263
+acc +33
+jmp +1
+nop +142
+jmp +78
+acc +41
+nop -141
+acc -9
+acc +5
+jmp -245
+jmp +41
+acc +16
+nop -83
+jmp -28
+nop -149
+acc +38
+jmp -15
+acc +7
+nop -329
+acc +5
+acc +21
+jmp -7
+acc -19
+jmp -38
+acc +5
+acc +3
+acc +10
+jmp -181
+jmp -240
+acc +19
+acc +15
+acc +31
+acc -11
+jmp -340
+acc +12
+acc +46
+jmp +127
+acc +12
+acc +31
+acc +30
+jmp -158
+acc -10
+jmp -374
+jmp +50
+acc +43
+nop +42
+acc +19
+jmp -232
+acc -14
+acc -4
+jmp +95
+acc +23
+acc +49
+acc +31
+nop -139
+jmp -272
+jmp -141
+acc +26
+acc -8
+jmp +173
+nop +145
+nop +133
+jmp +164
+acc +7
+jmp +23
+acc -4
+acc +48
+jmp -138
+acc +4
+jmp -389
+nop +156
+acc +44
+acc +40
+jmp +146
+nop -247
+acc +44
+jmp +1
+acc +28
+jmp +95
+acc +13
+acc +2
+jmp -254
+acc +24
+jmp +122
+acc +39
+acc +0
+jmp -12
+jmp -179
+nop -44
+nop +100
+acc -19
+nop -47
+jmp -107
+acc +32
+acc +33
+acc +42
+acc +6
+jmp -366
+jmp -122
+acc +2
+nop -443
+nop +72
+jmp -381
+jmp -446
+jmp -332
+acc -7
+acc +45
+jmp -355
+acc +27
+acc -4
+acc +3
+jmp +96
+acc +45
+jmp -402
+acc +45
+acc -3
+acc +22
+jmp -141
+acc +29
+acc -1
+jmp +29
+acc -1
+acc -10
+jmp -208
+acc +6
+nop -196
+jmp -218
+acc -12
+acc +49
+nop -137
+jmp -430
+acc +21
+jmp -110
+nop -287
+acc -3
+jmp -42
+jmp -487
+acc -16
+acc -1
+acc +7
+acc +39
+jmp -119
+jmp +1
+acc +9
+jmp -23
+acc +27
+jmp -300
+acc +12
+jmp -440
+acc +2
+acc +38
+acc +12
+jmp -84
+acc +25
+acc -14
+jmp -418
+acc -15
+acc +48
+jmp +1
+nop -383
+jmp -365
+acc +47
+jmp -193
+acc +23
+jmp -235
+jmp +1
+acc -4
+acc +35
+nop -64
+jmp -87
+acc +32
+jmp -339
+jmp -479
+acc -4
+acc +32
+acc -10
+jmp -77
+acc +0
+acc +47
+acc +41
+jmp -308
+acc -8
+acc -9
+jmp -229
+acc -14
+acc +24
+nop -380
+acc +49
+jmp -174
+acc -11
+nop -69
+jmp +3
+acc -14
+jmp -89
+jmp -301
+acc +46
+acc +8
+nop -156
+acc +44
+jmp +1
+jmp +26
+acc +17
+acc +23
+acc +6
+jmp -4
+jmp -97
+jmp -324
+acc +2
+jmp -27
+nop -195
+acc +3
+acc -13
+acc +15
+jmp -19
+acc +30
+nop -318
+jmp +19
+nop -72
+jmp -315
+acc +4
+nop +6
+jmp -384
+jmp -505
+jmp -512
+acc +33
+jmp -168
+jmp -443
+nop -519
+acc +7
+acc +41
+acc +15
+jmp -269
+nop -539
+jmp -416
+jmp -326
+nop -221
+acc +14
+jmp -186
+acc -1
+jmp -295
+acc +29
+acc +43
+nop -436
+nop -421
+jmp -123
+acc +13
+acc -11
+acc +12
+jmp -155
+acc +9
+acc -16
+acc -15
+nop -380
+jmp +1

2020/samples/08.txt

@@ -0,0 +1,9 @@
+nop +0
+acc +1
+jmp +4
+acc +3
+jmp -3
+acc -99
+acc +1
+jmp -4
+acc +6

2020/src/day08.rs

@@ -0,0 +1,123 @@
+use std::convert::Infallible;
+use std::io::Read;
+use std::str::FromStr;
+
+use crate::common::from_lines;
+use crate::Solution;
+
+#[derive(Debug, Copy, Clone)]
+enum Instruction {
+    Acc(i32),
+    Jmp(i32),
+    Nop(i32),
+}
+
+impl FromStr for Instruction {
+    type Err = Infallible;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut split = s.split(' ');
+
+        let command = split.next().unwrap();
+        let argument: i32 = split.next().unwrap().parse().unwrap();
+
+        let instruction = match command {
+            "nop" => Instruction::Nop(argument),
+            "acc" => Instruction::Acc(argument),
+            "jmp" => Instruction::Jmp(argument),
+            _ => panic!("Unknown command '{}'", command),
+        };
+
+        Ok(instruction)
+    }
+}
+
+fn run_program(program: &[Instruction]) -> (i32, usize) {
+    let mut accumulator = 0;
+    let mut pc = 0;
+    let mut visited = vec![false; program.len()];
+
+    while pc < program.len() {
+        if visited[pc] {
+            return (accumulator, pc);
+        }
+
+        visited[pc] = true;
+
+        match program[pc] {
+            Instruction::Acc(n) => accumulator += n,
+            Instruction::Jmp(n) => {
+                if n > 0 {
+                    pc += n as usize;
+                } else {
+                    pc -= (-n) as usize;
+                }
+                continue;
+            }
+            Instruction::Nop(_) => {}
+        }
+
+        pc += 1;
+    }
+
+    (accumulator, pc)
+}
+
+#[derive(Default)]
+pub struct Day08;
+
+impl Solution for Day08 {
+    fn part1(&mut self, input: &mut dyn Read) -> String {
+        let program: Vec<Instruction> = from_lines(input);
+        run_program(&program).0.to_string()
+    }
+
+    fn part2(&mut self, input: &mut dyn Read) -> String {
+        let mut program: Vec<Instruction> = from_lines(input);
+
+        for i in 0..program.len() {
+            if let Instruction::Nop(n) = program[i] {
+                program[i] = Instruction::Jmp(n);
+
+                let (acc, pc) = run_program(&program);
+
+                if pc == program.len() {
+                    return acc.to_string();
+                }
+
+                program[i] = Instruction::Nop(n);
+            } else if let Instruction::Jmp(n) = program[i] {
+                program[i] = Instruction::Nop(n);
+
+                let (acc, pc) = run_program(&program);
+
+                if pc == program.len() {
+                    return acc.to_string();
+                }
+
+                program[i] = Instruction::Jmp(n);
+            }
+        }
+
+        panic!("No solution found")
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::test_implementation;
+
+    use super::*;
+
+    const SAMPLE: &[u8] = include_bytes!("../samples/08.txt");
+
+    #[test]
+    fn sample_part1() {
+        test_implementation!(Day08, 1, SAMPLE, 5);
+    }
+
+    #[test]
+    fn sample_part2() {
+        test_implementation!(Day08, 2, SAMPLE, 8);
+    }
+}

2020/src/lib.rs

@@ -8,6 +8,7 @@ mod day04;
 mod day05;
 mod day06;
 mod day07;
+mod day08;
 
 pub trait Solution {
     fn part1(&mut self, input: &mut dyn Read) -> String;
@@ -26,6 +27,7 @@ pub fn get_implementation(day: usize) -> Box<dyn Solution> {
         5 => Box::new(day05::Day05::default()),
         6 => Box::new(day06::Day06::default()),
         7 => Box::new(day07::Day07::default()),
+        8 => Box::new(day08::Day08::default()),
         _ => panic!("Unsupported day {}", day),
     }
 }