From f18e7797edf8240569d0104e16dcf5fca75fbf76 Mon Sep 17 00:00:00 2001
From: Johannes <freelon@gmx.net>
Date: Thu, 27 Jun 2024 21:53:21 +0200
Subject: [PATCH] Day 17 part 1.

---
 src/day17.rs | 43 +++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs   |  1 +
 2 files changed, 44 insertions(+)
 create mode 100644 src/day17.rs

diff --git a/src/day17.rs b/src/day17.rs
new file mode 100644
index 0000000..0367614
--- /dev/null
+++ b/src/day17.rs
@@ -0,0 +1,43 @@
+use aoc_runner_derive::{aoc, aoc_generator};
+
+#[aoc_generator(day17)]
+fn parse(input: &str) -> Vec<u32> {
+    input.lines().map(|line| line.parse().unwrap()).collect()
+}
+
+#[aoc(day17, part1)]
+fn part1(input: &[u32]) -> usize {
+    bar(input, 150)
+}
+
+fn bar(containers: &[u32], target: u32) -> usize {
+    baz(containers, target, 0)
+}
+
+fn baz(containers: &[u32], target: u32, filled: u32) -> usize {
+    if filled > target {
+        return 0;
+    } else if filled == target {
+        return 1;
+    } else if containers.len() == 0 {
+        return 0;
+    }
+
+    baz(&containers[1..], target, filled + containers[0])
+        + baz(&containers[1..], target, filled)
+}
+
+#[aoc(day17, part2)]
+fn part2(_input: &[u32]) -> usize {
+    0
+}
+
+#[cfg(test)]
+mod test {
+    use crate::day17::bar;
+
+    #[test]
+    fn part1() {
+        assert_eq!(bar(&[20, 15, 10, 5, 5], 25), 4)
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 7e780e4..a6a81d4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -9,5 +9,6 @@ mod day13;
 mod day14;
 mod day15;
 mod day16;
+mod day17;
 
 aoc_lib! { year = 2015 }