From fe33824026ba8f2ab9c50a64274d5068a4686830 Mon Sep 17 00:00:00 2001
From: spectre <ole@benstem.de>
Date: Sat, 9 Dec 2023 12:38:12 +0100
Subject: [PATCH] removed redundancy

---
 aoc2023/src/day09.rs | 23 +++++------------------
 1 file changed, 5 insertions(+), 18 deletions(-)

diff --git a/aoc2023/src/day09.rs b/aoc2023/src/day09.rs
index 447fdc3..1cb47d0 100644
--- a/aoc2023/src/day09.rs
+++ b/aoc2023/src/day09.rs
@@ -10,22 +10,22 @@ impl Solution for Day09 {
             ).collect::<Vec<Vec<i64>>>();
 
         Answer::from(
-            lines.iter().map(solve1).sum::<i64>()
+            lines.iter().map(solve).sum::<i64>()
         )
     }
 
     fn part_2(&self, input: &str) -> Answer {
         let lines = input.split("\n")
-            .map(|l| l.split_whitespace().map(|x| x.parse::<i64>().unwrap()).collect()
+            .map(|l| l.split_whitespace().map(|x| x.parse::<i64>().unwrap()).rev().collect()
             ).collect::<Vec<Vec<i64>>>();
 
         Answer::from(
-            lines.iter().map(solve2).sum::<i64>()
+            lines.iter().map(solve).sum::<i64>()
         )
     }
 }
 
-fn solve1(seq: &Vec<i64>) -> i64 {
+fn solve(seq: &Vec<i64>) -> i64 {
     if seq.iter().all(|x| *x==0) {
         return 0
     }
@@ -34,18 +34,5 @@ fn solve1(seq: &Vec<i64>) -> i64 {
         .map(|(a, b)| b - a )
         .collect();
 
-    return seq.last().unwrap() + solve1(&diffs)
+    return seq.last().unwrap() + solve(&diffs)
 }
-
-fn solve2(seq: &Vec<i64>) -> i64 {
-    if seq.iter().all(|x| *x==0) {
-        return 0
-    }
-
-    let diffs = zip(seq, seq.iter().skip(1))
-        .map(|(a, b)| b - a )
-        .collect();
-
-    return seq.first().unwrap() - solve2(&diffs)
-}
-