feat: completed day 10

ankjevel · ankjevel · commit 95d02dc6f72d · 2020-12-10T22:16:15.000+01:00
diff --git a/README.md b/README.md
@@ -12,7 +12,7 @@
 - [Day 7](https://github.com/ankjevel/adventofcode/tree/2020/day_07) 🌟 🌟
 - [Day 8](https://github.com/ankjevel/adventofcode/tree/2020/day_08) 🌟 🌟
 - [Day 9](https://github.com/ankjevel/adventofcode/tree/2020/day_09) 🌟 🌟
-- [Day 10](#)
+- [Day 10](https://github.com/ankjevel/adventofcode/tree/2020/day_10) 🌟 🌟
 - [Day 11](#)
 - [Day 12](#)
 - [Day 13](#)
diff --git a/day_10/Cargo.toml b/day_10/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "day_10"
+version = "0.1.0"
+edition = "2018"
+authors = ["Dennis Pettersson <mail@dennispettersson.se>"]
+
+[lib]
+doctest = false
+
+[[bin]]
+name = "day_10"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/day_10/src/lib.rs b/day_10/src/lib.rs
@@ -0,0 +1,29 @@
+pub mod part_01;
+pub mod part_02;
+
+pub type Input = Vec<u32>;
+
+pub fn parse_input(input: &str) -> Input {
+    input
+        .lines()
+        .map(str::trim)
+        .filter(|string| !string.is_empty())
+        .map(|string| string.parse::<_>().unwrap_or(0))
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const EXAMPLE_DATA: &'static str = "
+        16
+        10
+        15
+    ";
+
+    #[test]
+    fn it_parses_example() {
+        assert_eq!(parse_input(&EXAMPLE_DATA), vec![16, 10, 15]);
+    }
+}
diff --git a/day_10/src/main.rs b/day_10/src/main.rs
@@ -0,0 +1,14 @@
+use std::io::Result;
+
+use day_10::{parse_input, part_01::main as part_01, part_02::main as part_02};
+
+fn main() -> Result<()> {
+    let input = parse_input(include_str!("../../input/day_10"));
+
+    println!("part_01: {:?}", part_01(&input)?);
+    println!("part_02: {:?}", part_02(&input)?);
+
+    Ok(())
+}
+
+
diff --git a/day_10/src/part_01.rs b/day_10/src/part_01.rs
@@ -0,0 +1,56 @@
+use std::io::Result;
+
+use crate::Input;
+
+pub fn main(input: &Input) -> Result<u32> {
+    let mut input = input.clone().to_owned();
+    input.sort();
+    input.push(*input.iter().max().unwrap() + 3);
+
+    let mut iter = input.iter_mut().peekable();
+    let mut jolt = 0;
+    let mut diff = (0, 0);
+    while iter.len() > 0 {
+        if let Some(next) = iter.peek() {
+            if !(jolt + 1..=jolt + 3).contains(*next) {
+                break;
+            }
+        }
+        let adapter = iter.next().unwrap();
+        match *adapter - jolt {
+            1 => diff.0 += 1,
+            3 => diff.1 += 1,
+            _ => (),
+        }
+        jolt = *adapter;
+    }
+    let (one_jolt, three_jolt) = diff;
+    Ok(one_jolt * three_jolt)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::parse_input;
+
+    use super::*;
+
+    const EXAMPLE_DATA: &'static str = "
+        16
+        10
+        15
+        5
+        1
+        11
+        7
+        19
+        6
+        12
+        4
+    ";
+
+    #[test]
+    fn it_gets_the_example_correct() -> Result<()> {
+        assert_eq!(main(&parse_input(&EXAMPLE_DATA))?, 35);
+        Ok(())
+    }
+}
diff --git a/day_10/src/part_02.rs b/day_10/src/part_02.rs
@@ -0,0 +1,89 @@
+use std::io::Result;
+
+use crate::Input;
+
+fn naive_recursion(jolt: u32, index: usize, adapters: &Vec<u32>) -> u64 {
+    let len = adapters.len();
+    if len == index {
+        return 1;
+    }
+    (index..=index + 3)
+        .filter(|i| i < &len && *adapters.get(*i).unwrap() <= jolt + 3)
+        .map(|i| naive_recursion(*adapters.get(i).unwrap(), i + 1, adapters))
+        .sum()
+}
+
+pub fn main(input: &Input) -> Result<u64> {
+    let mut adapters = input.clone().to_owned();
+    adapters.sort();
+    adapters.push(*adapters.iter().max().unwrap() + 3);
+
+    Ok(naive_recursion(0, 0, &adapters))
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::parse_input;
+
+    use super::*;
+
+    const SHORT_EXAMPLE_DATA: &'static str = "
+        16
+        10
+        15
+        5
+        1
+        11
+        7
+        19
+        6
+        12
+        4
+    ";
+
+    #[test]
+    fn it_gets_the_first_example_correct() -> Result<()> {
+        assert_eq!(main(&parse_input(&SHORT_EXAMPLE_DATA))?, 8);
+        Ok(())
+    }
+
+    const LONGER_EXAMPLE_DATA: &'static str = "
+        28
+        33
+        18
+        42
+        31
+        14
+        46
+        20
+        48
+        47
+        24
+        23
+        49
+        45
+        19
+        38
+        39
+        11
+        1
+        32
+        25
+        35
+        8
+        17
+        7
+        9
+        4
+        2
+        34
+        10
+        3
+    ";
+
+    #[test]
+    fn it_gets_the_longer_example_correct() -> Result<()> {
+        assert_eq!(main(&parse_input(&LONGER_EXAMPLE_DATA))?, 19208);
+        Ok(())
+    }
+}
diff --git a/input/day_10 b/input/day_10
@@ -0,0 +1,98 @@
+126
+38
+162
+123
+137
+97
+92
+67
+136
+37
+146
+2
+139
+74
+101
+163
+128
+127
+13
+111
+30
+117
+3
+93
+29
+152
+80
+21
+7
+54
+69
+40
+48
+104
+110
+142
+57
+116
+31
+70
+28
+151
+108
+20
+157
+121
+47
+75
+94
+39
+73
+77
+129
+41
+24
+44
+132
+87
+114
+58
+64
+4
+10
+19
+138
+45
+76
+147
+59
+155
+156
+83
+118
+109
+107
+160
+61
+91
+102
+115
+68
+150
+34
+16
+27
+135
+161
+46
+122
+90
+1
+164
+100
+103
+84
+145
+51
+60

-Original file line number
+Diff line change
@@ @@ -0,0 +1,98 @@ @@
 +126
 +38
 +162
 +123
 +137
 +97
 +92
 +67
 +136
 +37
 +146
 +2
 +139
 +74
 +101
 +163
 +128
 +127
 +13
 +111
 +30
 +117
 +3
 +93
 +29
 +152
 +80
 +21
 +7
 +54
 +69
 +40
 +48
 +104
 +110
 +142
 +57
 +116
 +31
 +70
 +28
 +151
 +108
 +20
 +157
 +121
 +47
 +75
 +94
 +39
 +73
 +77
 +129
 +41
 +24
 +44
 +132
 +87
 +114
 +58
 +64
 +4
 +10
 +19
 +138
 +45
 +76
 +147
 +59
 +155
 +156
 +83
 +118
 +109
 +107
 +160
 +61
 +91
 +102
 +115
 +68
 +150
 +34
 +16
 +27
 +135
 +161
 +46
 +122
 +90
 +1
 +164
 +100
 +103
 +84
 +145
 +51
 +60