From 032729045495207507f7fc05b77341ebf945f001 Mon Sep 17 00:00:00 2001
From: timeshifter <timeshifter@altaica>
Date: Mon, 24 Mar 2025 16:15:16 +0100
Subject: [PATCH] 46

---
 src/euler46/Cargo.toml  |  8 ++++++++
 src/euler46/src/main.rs | 26 ++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 src/euler46/Cargo.toml
 create mode 100644 src/euler46/src/main.rs

diff --git a/src/euler46/Cargo.toml b/src/euler46/Cargo.toml
new file mode 100644
index 0000000..7791fc9
--- /dev/null
+++ b/src/euler46/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "euler46"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+itertools = "0.14"
+primes = { version = "*", path = "../../lib/primes" }
diff --git a/src/euler46/src/main.rs b/src/euler46/src/main.rs
new file mode 100644
index 0000000..b3de9b9
--- /dev/null
+++ b/src/euler46/src/main.rs
@@ -0,0 +1,26 @@
+use primes::Primes;
+
+const MAX: usize = 1_000_000;
+
+fn main() {
+    let primes = Primes::get_between(2, MAX);
+    'outer: for number in iter_odd_composite_numbers(&primes) {
+        for prime in primes.iter().take_while(|p| **p < number) {
+            'inner: for n in 1_usize.. {
+                let sum = prime + 2 * n.pow(2);
+                if sum == number {
+                    continue 'outer;
+                }
+                if sum > number {
+                    break 'inner;
+                }
+            }
+        }
+        println!("{number}");
+        break 'outer;
+    }
+}
+
+fn iter_odd_composite_numbers(primes: &Primes<usize>) -> impl Iterator<Item = usize> {
+    (3..MAX).step_by(2).filter(|n| !primes.contains(n))
+}