Move code into a single cargo module with an execution harness.

2022/src/day01.rs

@@ -0,0 +1,52 @@
+use std::env;
+use std::io;
+use std::io::prelude::*;
+use std::fs::File;
+use sorted_vec::SortedVec;
+
+fn read_lines(filename: &str) -> io::Result<io::Lines<io::BufReader<File>>> {
+    let file = File::open(filename)?;
+    Ok(io::BufReader::new(file).lines())
+}
+
+fn get_step() -> i32 {
+    for arg in env::args() {
+        if arg == "2" { return 2 }
+    }
+    return 1
+}
+
+fn update_max(max: &mut SortedVec<i32>, current: i32, step: i32) {
+    if max.is_empty() {
+        max.insert(current);
+        return
+    }
+    if current <= max[0] { return }
+
+    max.insert(current);
+    match step {
+        2 => { if max.len() > 3 { max.remove_index(0); } },
+        _ => { max.remove_index(0); },
+    }
+}
+
+pub fn execute() -> Result<(), io::Error> {
+    let step = get_step();
+
+    let mut max: SortedVec<i32> = SortedVec::new();
+    let mut current = 0;
+
+    for line in read_lines("input/day01.txt")? {
+        let text = line?;
+        current = match text.parse::<i32>() {
+            Ok(value) => current + value,
+            Err(_) => {
+                update_max(&mut max, current, step);
+                0
+            },
+        }
+    }
+
+    println!("{}", max.iter().fold(0i32, |sum, i| sum + (*i as i32)));
+    Ok(())
+}