Challenge 072-1

1 files changed, 33 insertions, 0 deletions

diff --git a/challenge-072/wambash/raku/ch-1.raku b/challenge-072/wambash/raku/ch-1.raku
new file mode 100644
index 0000000000..52b915d5cd
--- /dev/null
+++ b/challenge-072/wambash/raku/ch-1.raku
@@ -0,0 +1,33 @@
+use v6;
+constant @fact = 1, |[\*] 1..* ;
+subset BigInt of Int where * ≥ 2000;
+
+multi trailing-zeroes ( $n ) {
+    @fact[$n].match(/0*$/).chars
+}
+
+multi trailing-zeroes ( BigInt $n ) {
+    trailing-zeroes-of-bigint($n)
+}
+
+sub trailing-zeroes-of-bigint ( $n ) {
+    state @coeficient = [\+] 0, {5**$++} ... *;
+    [+] $n.polymod(5 xx *) Z* @coeficient
+}
+
+multi MAIN ($n) {
+    my $fact = $n ~~ BigInt ?? "$n!" !! "$n! = @fact[$n]";
+    say "$fact has {trailing-zeroes($n)} trailing zeroes"
+}
+
+multi MAIN (:$test! ) {
+    use Test;
+    is trailing-zeroes(10), 2;
+    is trailing-zeroes(7),  1;
+    is trailing-zeroes(4),  0;
+    is trailing-zeroes-of-bigint(10), 2;
+    is trailing-zeroes-of-bigint(7),  1;
+    is trailing-zeroes-of-bigint(4),  0;
+    is trailing-zeroes-of-bigint($_), trailing-zeroes($_) for ^2000 .pick(20);
+    done-testing;
+}