From 3caa8876e4c1d71cf8973d0d78231f16a0cd5b93 Mon Sep 17 00:00:00 2001
From: Iru Cai <mytbk920423@gmail.com>
Date: Fri, 25 May 2018 00:16:47 +0800
Subject: 45, 46, 92

---
 euler45.myr | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 euler45.myr

(limited to 'euler45.myr')

diff --git a/euler45.myr b/euler45.myr
new file mode 100644
index 0000000..3bf53fc
--- /dev/null
+++ b/euler45.myr
@@ -0,0 +1,30 @@
+use std
+
+const main = {
+	for var n: uint64 = 144; true; n++
+		var hn = n * (n * 2 - 1)
+		/* find pentagonal pn = n(3n-1)/2 */
+		/* n' < 2/sqrt(3)*n */
+		var i: uint64 = n * 148 / 128
+		var pn = i * (i * 3 - 1) / 2
+		while pn > hn
+			i--
+			pn = i * (i * 3 - 1) / 2
+		;;
+		if (pn != hn)
+			continue
+		;;
+		/* find triangle tn = n(n+1)/2, n'<2n */
+		i = n*2
+		var tn = i * (i + 1) / 2
+		while tn > hn
+			i--
+			tn = i * (i + 1) / 2
+		;;
+		if (tn != hn)
+			continue
+		;;
+		std.put("n = {}, h[n] = {}\n", n, hn)
+		break
+	;;
+}
-- 
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