From 37bf0f6a60c1d6b3d91300260a66e56a771eca29 Mon Sep 17 00:00:00 2001
From: Russell Champoux <Russell.Champoux@coupa.com>
Date: Fri, 5 Dec 2025 10:43:46 -0500
Subject: [PATCH] day 05

---
 README.md            |  3 +-
 data/examples/05.txt | 11 ++++++
 src/bin/05.rs        | 87 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 data/examples/05.txt
 create mode 100644 src/bin/05.rs

diff --git a/README.md b/README.md
index fb99969..e78a2e2 100644
--- a/README.md
+++ b/README.md
@@ -15,8 +15,9 @@ Solutions for [Advent of Code](https://adventofcode.com/) in [Rust](https://www.
 | [Day 2](./src/bin/02.rs) | `225.7ms` | `250.4ms` |
 | [Day 3](./src/bin/03.rs) | `85.9µs` | `120.1µs` |
 | [Day 4](./src/bin/04.rs) | `227.4µs` | `1.9ms` |
+| [Day 5](./src/bin/05.rs) | `159.6µs` | `21.4µs` |
 
-**Total: 480.16ms**
+**Total: 480.34ms**
 <!--- benchmarking table --->
 
 ---
diff --git a/data/examples/05.txt b/data/examples/05.txt
new file mode 100644
index 0000000..2e9078d
--- /dev/null
+++ b/data/examples/05.txt
@@ -0,0 +1,11 @@
+3-5
+10-14
+16-20
+12-18
+
+1
+5
+8
+11
+17
+32
diff --git a/src/bin/05.rs b/src/bin/05.rs
new file mode 100644
index 0000000..1e2dc5f
--- /dev/null
+++ b/src/bin/05.rs
@@ -0,0 +1,87 @@
+advent_of_code::solution!(5);
+use itertools::Itertools;
+
+pub fn part_one(input: &str) -> Option<u64> {
+    let lists = input.split("\n\n").collect_vec();
+    let ranges = lists[0]
+        .lines()
+        .map(|line| {
+            let (start, end) = line.split_once('-').unwrap();
+            // println!("Parsed range: {}-{}", start, end);
+            (start.parse::<u64>().unwrap(), end.parse::<u64>().unwrap())
+        })
+        .collect_vec();
+    let ids = lists[1].lines().map(|line| line.parse::<u64>().unwrap()).collect_vec();
+
+    // println!("{ranges:?}");
+    // println!("{ids:?}");
+    let mut fresh_item_count = 0;
+
+    for id in ids {
+        for (start, end) in &ranges {
+            if id >= *start && id <= *end {
+                // println!("ID {id} is in range {start}-{end}");
+                fresh_item_count += 1;
+                break;
+            }
+        }
+    }
+
+    Some(fresh_item_count)
+}
+
+pub fn part_two(input: &str) -> Option<u64> {
+    let lists = input.split("\n\n").collect_vec();
+    let mut ranges = lists[0]
+        .lines()
+        .map(|line| {
+            let (start, end) = line.split_once('-').unwrap();
+            // println!("Parsed range: {}-{}", start, end);
+            (start.parse::<u64>().unwrap(), end.parse::<u64>().unwrap())
+        })
+        .collect_vec();
+    ranges.sort_by(|a, b| if a.0 != b.0 {
+            a.0.cmp(&b.0)
+        } else {
+            a.1.cmp(&b.1)
+        });
+    // println!("{ranges:?}");
+
+    let mut i = 0;
+    while i < ranges.len() - 1 {
+        let (start_a, end_a) = ranges[i];
+        let (start_b, end_b) = ranges[i + 1];
+        if end_a >= start_b {
+            let new_end = end_a.max(end_b);
+            ranges[i] = (start_a, new_end);
+            ranges.remove(i + 1);
+            // println!("Merged to: {:?}", ranges[i]);
+        }
+        else {
+            i += 1;
+        }
+    }
+    // println!("{ranges:?}");
+
+    let total_count = ranges.iter().map(|(start, end)| end - start + 1).sum::<u64>();
+    // sort and merge ranges
+
+    Some(total_count)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(3));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(14));
+    }
+}