From 3183f0b695018c7450e8c442b2404595c895efb1 Mon Sep 17 00:00:00 2001
From: Ben Davies <kaiepi@outlook.com>
Date: Tue, 5 Oct 2021 17:41:43 -0300
Subject: Revise Ben Davies' challenge 133 task 1 solution

Actually use one of the square root algorithms suggested.
---
 challenge-133/ben-davies/raku/ch-1.raku | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/challenge-133/ben-davies/raku/ch-1.raku b/challenge-133/ben-davies/raku/ch-1.raku
index 98fd70d0ee..44ce0d2ba2 100644
--- a/challenge-133/ben-davies/raku/ch-1.raku
+++ b/challenge-133/ben-davies/raku/ch-1.raku
@@ -1,4 +1,12 @@
 use v6;
 unit sub MAIN(Int:D $n where * > 0) {
-    say (1..$n).first({ $^x == $n div $^x });
+    # Newton's method. Adapted from Algorithm 1.13 of:
+    # https://maths-people.anu.edu.au/~brent/pd/mca-cup-0.5.9.pdf
+    my $x;
+    my $L = $n;
+    repeat {
+        $x = $L;
+        $L = ($x + $n div $x) div 2;
+    } until $L >= $x;
+    say $x;
 }
-- 
cgit