From 27e936c22a8b5603e7621a592bf3497113f301a5 Mon Sep 17 00:00:00 2001
From: Simon Gardling <titaniumtown@proton.me>
Date: Mon, 27 Jan 2025 22:34:45 -0500
Subject: [PATCH] improve split_from

---
 src/misc.rs | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/misc.rs b/src/misc.rs
index ed7c476..929ac93 100644
--- a/src/misc.rs
+++ b/src/misc.rs
@@ -4,7 +4,17 @@ pub fn split_from(min: usize, max: usize, x: usize) -> Vec<Vec<usize>> {
     }
     let x_lower = x.checked_sub(1).unwrap_or(min);
     let x_upper = (x + 1).min(max);
-    vec![(min..=x_lower).rev().collect(), (x_upper..=max).collect()]
+    let lower_range = if x_lower != min {
+        (min..=x_lower).rev().collect()
+    } else {
+        Vec::new()
+    };
+    let upper_range = if x_upper != max {
+        (x_upper..=max).collect()
+    } else {
+        Vec::new()
+    };
+    vec![lower_range, upper_range]
 }
 
 #[cfg(test)]
@@ -14,5 +24,9 @@ mod test {
     #[test]
     fn split_test() {
         assert_eq!(split_from(0, 6, 2), vec![vec![1, 0], vec![3, 4, 5, 6]]);
+
+        assert_eq!(split_from(0, 6, 0), vec![vec![], vec![1, 2, 3, 4, 5, 6]]);
+
+        assert_eq!(split_from(0, 6, 6), vec![vec![5, 4, 3, 2, 1, 0], vec![]]);
     }
 }