From 11b75c6e601345fc5fc9c46ba6aa8ce8c9dae7c2 Mon Sep 17 00:00:00 2001
From: Coin de Gamma <cg@corpglory.com>
Date: Sun, 17 Dec 2023 13:11:15 +0000
Subject: [PATCH] 045

---
 045/main.rs | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 045/main.rs

diff --git a/045/main.rs b/045/main.rs
new file mode 100644
index 0000000..195c06c
--- /dev/null
+++ b/045/main.rs
@@ -0,0 +1,16 @@
+use std::collections::HashSet;
+
+fn main() {
+    let mut ps = HashSet::new();
+    let mut hs = HashSet::new();
+    let N = 500000u64;
+    for n in 1..N { hs.insert(n*(2*n-1)); }
+    for n in 1..N { ps.insert(n*(3*n -1)/2 ); }
+    for n in 286u64..N {
+        let tn = n * (n+1)/2;
+        if !hs.contains(&tn) { continue; }
+        if !ps.contains(&tn) { continue; }
+        println!("{}", tn);
+        break;
+    }
+}