From aec57c8690d4efd8f294f3ecd96dc5c8afb723a8 Mon Sep 17 00:00:00 2001
From: Nick Krichevsky <nick@ollien.com>
Date: Thu, 9 Dec 2021 02:11:30 -0500
Subject: [PATCH] Make input parsing more defensive

---
 day9/src/main.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/day9/src/main.rs b/day9/src/main.rs
index 78f08e9..ccbc6ed 100644
--- a/day9/src/main.rs
+++ b/day9/src/main.rs
@@ -157,6 +157,12 @@ fn main() {
         })
         .collect::<Vec<_>>();
 
+    let first_row_length = input_lines.get(0).expect("input must be non-empty").len();
+    assert!(
+        input_lines.iter().all(|row| row.len() == first_row_length),
+        "All input lines must be the same length"
+    );
+
     println!("Part 1: {}", part1(&input_lines));
     println!("Part 2: {}", part2(&input_lines));
 }