From 2c3840f65a0bfe39bf27f89c0892df600f00f01c Mon Sep 17 00:00:00 2001
From: Candygoblen123 <andrew.glaze76@gmail.com>
Date: Mon, 11 Dec 2023 09:52:06 -0500
Subject: [PATCH] day9 part2

---
 day09/src/main.rs | 44 ++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 40 insertions(+), 4 deletions(-)

diff --git a/day09/src/main.rs b/day09/src/main.rs
index eb7fc20..745222c 100644
--- a/day09/src/main.rs
+++ b/day09/src/main.rs
@@ -12,7 +12,7 @@ fn main() {
     let mut total = 0;
 
     for line in input {
-        let mut line_enders: Vec<i64> = vec![*line.last().unwrap()];
+        let mut line_starters: Vec<i64> = vec![*line.first().unwrap()];
         let mut cur_line: Vec<i64> = line;
         while !cur_line.iter().all(|x| *x == 0) {
             let mut next_line: Vec<i64> = vec![];
@@ -20,15 +20,51 @@ fn main() {
                 let diff = cur_line[i] - cur_line[i-1];
                 next_line.push(diff)
             }
-            line_enders.push(*next_line.last().unwrap());
+            line_starters.push(*next_line.first().unwrap());
             cur_line = next_line;
         }
 
         let mut sum = 0;
-        for i in (1..line_enders.len()).rev() {
-            sum = sum + line_enders[i - 1];
+        for i in (1..line_starters.len()).rev() {
+            sum = line_starters[i - 1] - sum;
         }
         total += sum;
     }
     println!("{:?}", total)
 }
+
+
+// use std::fs;
+
+// fn main() {
+//     let input = fs::read_to_string("input.txt").unwrap();
+//     let input: Vec<_> = input.split('\n')
+//         .map(|line| {
+//             line.split_whitespace()
+//                 .map(|num| num.parse::<i64>().unwrap())
+//                 .collect::<Vec<_>>()
+//         }).collect();
+
+//     let mut total = 0;
+
+//     for line in input {
+//         let mut line_enders: Vec<i64> = vec![*line.last().unwrap()];
+//         let mut cur_line: Vec<i64> = line;
+//         while !cur_line.iter().all(|x| *x == 0) {
+//             let mut next_line: Vec<i64> = vec![];
+//             for i in 1..cur_line.len() {
+//                 let diff = cur_line[i] - cur_line[i-1];
+//                 next_line.push(diff)
+//             }
+//             line_enders.push(*next_line.last().unwrap());
+//             cur_line = next_line;
+//         }
+
+//         let mut sum = 0;
+//         for i in (1..line_enders.len()).rev() {
+//             sum = sum + line_enders[i - 1];
+//         }
+//         total += sum;
+//     }
+//     println!("{:?}", total)
+// }