Day 5, puzzle 1

src/bin/d5p1.rs

@@ -0,0 +1,25 @@
+use aoc22::{day5, util};
+
+pub fn main() {
+    let mut arrangement = day5::parse_arrangement(&util::parse_input());
+
+    for inst in &arrangement.instructions {
+        for _ in 0..inst.num {
+            let box_ = arrangement
+                .stacks
+                .get_mut(inst.from)
+                .unwrap()
+                .pop_back()
+                .unwrap();
+            arrangement.stacks.get_mut(inst.to).unwrap().push_back(box_);
+        }
+    }
+
+    let top_boxes: String = arrangement
+        .stacks
+        .iter()
+        .map(|s| s.iter().next_back().unwrap())
+        .collect();
+
+    println!("The top boxes are {}", top_boxes);
+}