From a13fd2afe7256ad33fbd0aa909936480d0b16ca8 Mon Sep 17 00:00:00 2001
From: Joshua Smallwood <31932412+smallwoj@users.noreply.github.com>
Date: Sat, 6 Dec 2025 13:38:33 -0600
Subject: [PATCH] feat: solve day 5

---
 data/examples/05-1.txt | 11 +++++
 data/examples/05-2.txt |  6 +++
 data/examples/05-3.txt |  6 +++
 src/bin/05.rs          | 92 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 115 insertions(+)
 create mode 100644 data/examples/05-1.txt
 create mode 100644 data/examples/05-2.txt
 create mode 100644 data/examples/05-3.txt
 create mode 100644 src/bin/05.rs

diff --git a/data/examples/05-1.txt b/data/examples/05-1.txt
new file mode 100644
index 0000000..2e9078d
--- /dev/null
+++ b/data/examples/05-1.txt
@@ -0,0 +1,11 @@
+3-5
+10-14
+16-20
+12-18
+
+1
+5
+8
+11
+17
+32
diff --git a/data/examples/05-2.txt b/data/examples/05-2.txt
new file mode 100644
index 0000000..dab38b6
--- /dev/null
+++ b/data/examples/05-2.txt
@@ -0,0 +1,6 @@
+1-10
+2-9
+3-8
+4-7
+5-6
+
diff --git a/data/examples/05-3.txt b/data/examples/05-3.txt
new file mode 100644
index 0000000..c21cf26
--- /dev/null
+++ b/data/examples/05-3.txt
@@ -0,0 +1,6 @@
+5-6
+4-7
+1-10
+3-8
+2-9
+
diff --git a/src/bin/05.rs b/src/bin/05.rs
new file mode 100644
index 0000000..9e717b7
--- /dev/null
+++ b/src/bin/05.rs
@@ -0,0 +1,92 @@
+use itertools::Itertools;
+
+advent_of_code::solution!(5);
+
+pub fn part_one(input: &str) -> Option<usize> {
+    let mut input_iter = input.splitn(2, "\n\n");
+    let ranges = input_iter.next().unwrap().split("\n").map(|range| {
+        let mut range_iter = range.split("-");
+        let start = range_iter.next().unwrap().parse::<u128>().unwrap_or(0);
+        let end = range_iter.next().unwrap().parse::<u128>().unwrap_or(0);
+        start..end + 1
+    });
+    Some(
+        input_iter
+            .next()
+            .unwrap()
+            .split("\n")
+            .filter(|id| !id.is_empty())
+            .map(|id| id.parse::<u128>().unwrap())
+            .filter(|id| {
+                let mut found = false;
+                for range in ranges.clone() {
+                    if range.contains(id) {
+                        found = true;
+                        break;
+                    }
+                }
+                found
+            })
+            .count(),
+    )
+}
+
+pub fn part_two(input: &str) -> Option<i128> {
+    let mut input_iter = input.splitn(2, "\n\n");
+    let ranges = input_iter
+        .next()
+        .unwrap()
+        .split("\n")
+        .map(|range| {
+            let mut range_iter = range.split("-");
+            let start = range_iter.next().unwrap().parse::<i128>().unwrap_or(0);
+            let end = range_iter.next().unwrap().parse::<i128>().unwrap_or(0);
+            (start, end)
+        })
+        .sorted_by_key(|(start, _)| *start)
+        .collect::<Vec<(i128, i128)>>();
+    let mut merged_ranges: Vec<(i128, i128)> = vec![];
+
+    for range in ranges {
+        if let Some(last) = merged_ranges.last_mut() {
+            if range.0 <= last.1 + 1 {
+                last.1 = std::cmp::max(last.1, range.1);
+                continue;
+            }
+        }
+        merged_ranges.push(range);
+    }
+    merged_ranges
+        .iter()
+        .map(|(start, end)| end - start + 1)
+        .sum1()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file_part(
+            "examples", DAY, 1,
+        ));
+        assert_eq!(result, Some(3));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let mut result = part_two(&advent_of_code::template::read_file_part(
+            "examples", DAY, 1,
+        ));
+        assert_eq!(result, Some(14));
+        result = part_two(&advent_of_code::template::read_file_part(
+            "examples", DAY, 2,
+        ));
+        assert_eq!(result, Some(10));
+        result = part_two(&advent_of_code::template::read_file_part(
+            "examples", DAY, 3,
+        ));
+        assert_eq!(result, Some(10));
+    }
+}