From 898ba7669352cbd368d5f3833f182160537c3a9f Mon Sep 17 00:00:00 2001
From: timeshifter <timeshifter@altaica>
Date: Mon, 17 Mar 2025 16:21:23 +0100
Subject: [PATCH] 28

---
 src/euler28/Cargo.toml  |  6 ++++++
 src/euler28/src/main.rs | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100644 src/euler28/Cargo.toml
 create mode 100644 src/euler28/src/main.rs

diff --git a/src/euler28/Cargo.toml b/src/euler28/Cargo.toml
new file mode 100644
index 0000000..aa6c309
--- /dev/null
+++ b/src/euler28/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "euler28"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
diff --git a/src/euler28/src/main.rs b/src/euler28/src/main.rs
new file mode 100644
index 0000000..aeb9f90
--- /dev/null
+++ b/src/euler28/src/main.rs
@@ -0,0 +1,34 @@
+fn main() {
+    let result = spiral(1001);
+    println!("{result}");
+}
+
+fn spiral(edge_length: usize) -> usize {
+    let max = edge_length * edge_length;
+    let mut sum = 1;
+    let mut number = 1;
+    let mut offset = 2;
+    let steps = 4;
+    loop {
+        for _ in 0..steps {
+            number += offset;
+            sum += number;
+        }
+        offset += 2;
+        if number == max {
+            break;
+        }
+    }
+
+    sum
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::spiral;
+
+    #[test]
+    fn spiral_5() {
+        assert_eq!(spiral(5), 101);
+    }
+}