switched to workspaces.

This should let me make a cross-day library.

days/day05/src/part2.rs

@@ -0,0 +1,48 @@
+use crate::utilities::*;
+
+pub fn part2(input: &(WorkArea, Vec<Move>)) -> Vec<char> {
+    let (mut work_area, moves) = input.to_owned();
+    for r#move in moves {
+        work_area.apply_move_cratemover9001(&r#move)
+    }
+    work_area
+        .get_stacks()
+        .iter()
+        .map(|stack| stack.last().unwrap().to_owned())
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part2() {
+        let input = (
+            WorkArea::new(vec![vec!['Z', 'N'], vec!['M', 'C', 'D'], vec!['P']]),
+            vec![
+                Move {
+                    to: 1,
+                    from: 2,
+                    number: 1,
+                },
+                Move {
+                    to: 3,
+                    from: 1,
+                    number: 3,
+                },
+                Move {
+                    to: 1,
+                    from: 2,
+                    number: 2,
+                },
+                Move {
+                    to: 2,
+                    from: 1,
+                    number: 1,
+                },
+            ],
+        );
+        assert_eq!(part2(&input), vec!['M', 'C', 'D']);
+    }
+}