From 18bdad10c27d199a4085655ce93902d4bba0d534 Mon Sep 17 00:00:00 2001
From: Justin Wernick <justin@worthe-it.co.za>
Date: Wed, 1 Dec 2021 08:44:23 +0200
Subject: Day 1

---
 .gitignore       |    2 +
 Cargo.lock       |   86 +++
 Cargo.toml       |    9 +
 inputs/day_1.txt | 2000 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 readme.org       |    2 +
 src/bin/day_1.rs |   78 +++
 src/lib.rs       |    1 +
 src/parsers.rs   |    6 +
 8 files changed, 2184 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Cargo.lock
 create mode 100644 Cargo.toml
 create mode 100644 inputs/day_1.txt
 create mode 100644 readme.org
 create mode 100644 src/bin/day_1.rs
 create mode 100644 src/lib.rs
 create mode 100644 src/parsers.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..53eaa21
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+/target
+**/*.rs.bk
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000..f047963
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,86 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aoc2021"
+version = "0.1.0"
+dependencies = [
+ "derive_more",
+ "nom",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2159be042979966de68315bce7034bb000c775f22e3e834e1c52ff78f041cae8"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "memchr"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
+
+[[package]]
+name = "minimal-lexical"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
+
+[[package]]
+name = "nom"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b1d11e1ef389c76fe5b81bcaf2ea32cf88b62bc494e19f493d0b30e7a930109"
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+ "minimal-lexical",
+ "version_check",
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+ "unicode-xid",
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+[[package]]
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+checksum = "053a8c8bcc71fcce321828dc897a98ab9760bef03a4fc36693c231e5b3216cfe"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "syn"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dff0acdb207ae2fe6d5976617f887eb1e35a2ba52c13c7234c790960cdad9238"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
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+[[package]]
+name = "unicode-xid"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
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+[[package]]
+name = "version_check"
+version = "0.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5fecdca9a5291cc2b8dcf7dc02453fee791a280f3743cb0905f8822ae463b3fe"
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..8906e7e
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "aoc2021"
+version = "0.1.0"
+authors = ["Justin Wernick <justin@worthe-it.co.za>"]
+edition = "2021"
+
+[dependencies]
+derive_more = "0.99.2"
+nom = "7.0.0"
diff --git a/inputs/day_1.txt b/inputs/day_1.txt
new file mode 100644
index 0000000..42f77f8
--- /dev/null
+++ b/inputs/day_1.txt
@@ -0,0 +1,2000 @@
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diff --git a/readme.org b/readme.org
new file mode 100644
index 0000000..642364f
--- /dev/null
+++ b/readme.org
@@ -0,0 +1,2 @@
+* Advent of Code 2021
+
diff --git a/src/bin/day_1.rs b/src/bin/day_1.rs
new file mode 100644
index 0000000..7b89d69
--- /dev/null
+++ b/src/bin/day_1.rs
@@ -0,0 +1,78 @@
+use aoc2021::parsers;
+use nom::{character::complete::line_ending, combinator::map, multi::separated_list1, IResult};
+use std::fs;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let input = fs::read_to_string("inputs/day_1.txt")?;
+    let sonar_scan = parse_sonar_scan(&input).unwrap().1;
+
+    {
+        let mut simple_increase_counter = DepthIncreaseCounter::default();
+        for (depth, next_depth) in sonar_scan.iter().zip(sonar_scan.iter().skip(1)) {
+            if next_depth > depth {
+                simple_increase_counter.increment();
+            }
+        }
+        dbg!(simple_increase_counter);
+    }
+
+    {
+        let windowed_sonar_scan = sonar_scan
+            .iter()
+            .zip(sonar_scan.iter().skip(1))
+            .zip(sonar_scan.iter().skip(2))
+            .map(|((depth1, depth2), depth3)| ThreeDepthWindowSum::new([*depth1, *depth2, *depth3]))
+            .collect::<Vec<_>>();
+
+        let mut windowed_increase_counter = DepthIncreaseCounter::default();
+        for (depth, next_depth) in windowed_sonar_scan
+            .iter()
+            .zip(windowed_sonar_scan.iter().skip(1))
+        {
+            if next_depth > depth {
+                windowed_increase_counter.increment();
+            }
+        }
+        dbg!(windowed_increase_counter);
+    }
+
+    Ok(())
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy)]
+struct Depth(u64);
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy)]
+struct ThreeDepthWindowSum(u64);
+
+impl ThreeDepthWindowSum {
+    fn new(depths: [Depth; 3]) -> ThreeDepthWindowSum {
+        ThreeDepthWindowSum(depths.into_iter().map(|d| d.0).sum())
+    }
+}
+
+fn parse_sonar_scan(input: &str) -> IResult<&str, Vec<Depth>> {
+    separated_list1(line_ending, parse_depth)(input)
+}
+
+fn parse_depth(input: &str) -> IResult<&str, Depth> {
+    map(parsers::u64, |number| Depth(number))(input)
+}
+
+#[derive(Default, Debug)]
+struct DepthIncreaseCounter(u64);
+
+impl DepthIncreaseCounter {
+    fn increment(&mut self) {
+        self.0 += 1;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn parses_a_depth() {
+        assert_eq!(parse_depth("96\n"), Ok(("\n", Depth(96))));
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..be756a0
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1 @@
+pub mod parsers;
diff --git a/src/parsers.rs b/src/parsers.rs
new file mode 100644
index 0000000..27b2aad
--- /dev/null
+++ b/src/parsers.rs
@@ -0,0 +1,6 @@
+use nom::{character::complete::digit1, combinator::map_res, IResult};
+use std::str::FromStr;
+
+pub fn u64(input: &str) -> IResult<&str, u64> {
+    map_res(digit1, |number| u64::from_str(number))(input)
+}
-- 
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