Add solution to day 1

1 files changed, 47 insertions, 0 deletions

diff --git a/src/day_1.rs b/src/day_1.rs
new file mode 100644
index 0000000..6632baa
--- /dev/null
+++ b/src/day_1.rs
@@ -0,0 +1,47 @@
+pub fn run(input: Vec<String>)
+{
+    // Convert inputs to unsigned integer numbers
+    let input: Vec<u32> = input
+        .into_iter()
+        .map(|s| {
+            s.parse()
+                .expect("All lines are required to be unsigned integers")
+        })
+        .collect();
+
+    part1(&input);
+    part2(&input);
+}
+
+fn part1(input: &[u32])
+{
+    let mut last_depth = u32::MAX;
+    let num_down_slopes = input
+        .iter()
+        .filter(|&depth| {
+            let going_deeper = *depth > last_depth;
+            last_depth = *depth;
+
+            going_deeper
+        })
+        .count();
+
+    println!("Solution to part 1: {}", num_down_slopes);
+}
+
+fn part2(input: &[u32])
+{
+    let mut last_aliased_depth = u32::MAX;
+    let num_aliased_down_slopes = input
+        .windows(3)
+        .filter(|&depths| {
+            let aliased_depth: u32 = depths.iter().sum();
+            let going_deeper = aliased_depth > last_aliased_depth;
+            last_aliased_depth = aliased_depth;
+
+            going_deeper
+        })
+        .count();
+
+    println!("Solution to part 2: {}", num_aliased_down_slopes);
+}