day 2 part 2

src/day02.rs

@@ -1,11 +1,11 @@
-use std::fs::read_to_string;
+use std::{default, fs::read_to_string};
 
 use itertools::Itertools;
 
 pub fn day_main() {
     let input = read_to_string("input/day02.txt").unwrap();
     println!("part1: {}", part1(&input));
-    // println!("part2: {}", part2(&input));
+    println!("part2: {}", part2(&input));
 }
 
 fn part1(input: &str) -> usize {
@@ -16,21 +16,43 @@ fn part1(input: &str) -> usize {
                 .map(|s| s.parse::<i32>().unwrap())
                 .collect_vec()
         })
-        .filter(|report: &Vec<i32>| {
+        .filter(|report: &Vec<i32>| is_safe(report))
-            let pairs = report
+        .count()
-                .windows(2)
+}
-                .map(|window| window[1] - window[0])
-                .collect_vec();
-            let steepest_slope = pairs.iter().map(|x| x.abs()).max().unwrap();
-            let lowest_slope = pairs.iter().map(|x| x.abs()).min().unwrap();
-            let same_sign = pairs.iter().map(|x| x.signum()).unique().count() == 1;
-            println!("{:?} - {steepest_slope}/{same_sign}", report);
 
-            steepest_slope <= 3 && lowest_slope >= 1 && same_sign
+fn part2(input: &str) -> usize {
+    input
+        .lines()
+        .map(|line| {
+            line.split_whitespace()
+                .map(|s| s.parse::<i32>().unwrap())
+                .collect_vec()
+        })
+        .filter(|report: &Vec<i32>| {
+            (0..report.len()).any(|del| {
+                let without = report
+                    .iter()
+                    .enumerate()
+                    .filter_map(|(i, e)| if del != i { Some(*e) } else { None })
+                    .collect_vec();
+                is_safe(&without)
+            })
         })
         .count()
 }
 
+fn is_safe(report: &[i32]) -> bool {
+    let pairs = report
+        .windows(2)
+        .map(|window| window[1] - window[0])
+        .collect_vec();
+    let steepest_slope = pairs.iter().map(|x| x.abs()).max().unwrap();
+    let lowest_slope = pairs.iter().map(|x| x.abs()).min().unwrap();
+    let same_sign = pairs.iter().map(|x| x.signum()).unique().count() == 1;
+
+    steepest_slope <= 3 && lowest_slope >= 1 && same_sign
+}
+
 // fn part2(input: &str) -> Int {
 //     0
 // }