day1

.gitignore

@@ -1,2 +1,3 @@
-/target
+target/
 input
+testinput

day01/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day01"
+version = "0.1.0"

day01/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "day01"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

day01/src/main.rs

@@ -0,0 +1,30 @@
+use std::io::{self, BufRead};
+
+fn main() {
+    let lines = io::stdin().lock().lines().map(|l| l.unwrap());
+    let mut sum = 0;
+    let mut max = [0, 0, 0];
+
+    for line in lines {
+        if let Ok(num) = line.parse::<usize>() {
+            sum += num;
+        } else {
+            match (sum > max[0], sum > max[1], sum > max[2]) {
+                (_, _, true) => {
+                    max.rotate_left(1);
+                    max[2] = sum;
+                }
+                (_, true, false) => {
+                    max[0] = max[1];
+                    max[1] = sum;
+                }
+                (true, false, false) => {
+                    max[0] = sum;
+                }
+                _ => (),
+            }
+            sum = 0;
+        }
+    }
+    println!("P1: {} P2: {}", max[2], max.iter().sum::<usize>());
+}

fetchinput.sh

@@ -2,7 +2,7 @@
 # AOC_SESSION_COOKIE="samplecookie" ./fetchinput.sh 13
 
 # defaults to current day unless specified day is passed in
-DAY=`date +%d`
+DAY=$(printf "%01d" `date +%d`)
 ! [ "$1" = "" ] && printf "%d" $1 >/dev/null 2>&1 && DAY=$1
 
 [ "$AOC_SESSION_COOKIE" = "" ] && echo "\$AOC_SESSION_COOKIE not set" && exit 1