From 7bfc78b122ad9cbb65eed16f7de4d4021547c2a8 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Sat, 23 Mar 2024 19:18:16 +0100
Subject: Some Project Euler solutions

---
 samples/euler/004.bruijn | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 samples/euler/004.bruijn

(limited to 'samples/euler/004.bruijn')

diff --git a/samples/euler/004.bruijn b/samples/euler/004.bruijn
new file mode 100644
index 0000000..e04cb4c
--- /dev/null
+++ b/samples/euler/004.bruijn
@@ -0,0 +1,19 @@
+# TODO: This has serious performance problems
+
+:import std/Combinator .
+:import std/List .
+:import std/Math .
+
+# palindrome? S.number→string → [S.eq? S.<~>0 0]
+
+palindrome? [y [[[&[[>?2 (4 (3 ⋅ (+10) + 0) 1) (3 =? 5)]] (quot-rem 0 (+10))]]] (+0) 0]
+
+# combs [[S.concat-map [S.map (mul 0) ({ 0 → 1 })] ({ ((+10) ** --1) → 0 })] --((+10) ** 0)]
+
+solve [[y [[[0 =? 3 1 rec]]] empty ((+10) ** --1)] ((+10) ** 0)] → lmax
+	rec 2 (comb ++ 1) ++0
+		comb y [[[0 =? 6 1 (2 ([palindrome? 0 (0 : 2) 2] (3 ⋅ 0)) ++0)]]] empty 0
+
+:test ((solve (+2)) =? (+9009)) ([[1]])
+
+main [solve (+3)]
-- 
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