day 2 almost part 2

2024/data/02/1.in

@@ -0,0 +1,6 @@
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9

2024/data/02/1.part1.out

@@ -0,0 +1 @@
+2

2024/data/02/1.part2.out

@@ -0,0 +1 @@
+4

2024/src/bin/02.rs

@@ -0,0 +1,67 @@
+use std::{fs::File, io::{BufRead, BufReader}};
+
+use anyhow::Result;
+use aoc2024::{Context, Day};
+use itertools::Itertools;
+
+fn part1(ctx: &Context) -> Result<String> {
+    Ok(BufReader::new(File::open(&ctx.args.input)?).lines().map(|line| {
+        let line = line.unwrap();
+        let mut rising = None;
+        let nums = line.split_whitespace().map(|n| n.parse::<u32>().unwrap()).tuple_windows().all(|(a,b)| valid(a,b, &mut rising));
+    
+        nums
+    }).map(|r| r as i32).sum::<i32>().to_string())
+}
+
+fn valid(a: u32, b: u32, rising: &mut Option<bool>) -> bool {
+    let diff = a.abs_diff(b);
+    if !(1..=3).contains(&diff) { return false }
+    match &rising {
+        None => {
+            *rising = Some(b > a);
+            true
+        },
+        Some(r) => {
+            if *r {
+                b > a
+            } else {
+                b < a
+            }
+        }
+    }
+}
+
+fn part2(ctx: &Context) -> Result<String> {
+    Ok(BufReader::new(File::open(&ctx.args.input)?).lines().map(|line| {
+        let mut found = false;
+        let mut skip = 0;
+        let line = line.unwrap();
+        let mut rising = None;
+        let nums = line.split_whitespace().map(|n| n.parse::<u32>().unwrap()).tuple_windows().all(|(a,b,c)| {
+            if skip > 0 {
+                skip -= 1;
+                return true
+            }
+            if valid(a,b,&mut rising) {
+                true
+            } else {
+                if found { return false }
+                found = true;
+                skip = 1;
+
+                valid(a, c, &mut rising)
+            }
+        });
+    
+        nums
+    })
+    .map(|r| r as i32).sum::<i32>().to_string())
+}
+
+fn main() {
+    Day::new()
+        .part1(part1)
+        .part2(part2)
+        .run();
+}