add solution week 133 task 1 in perl

1 files changed, 25 insertions, 0 deletions

diff --git a/challenge-133/steven-wilson/perl/ch-1.pl b/challenge-133/steven-wilson/perl/ch-1.pl
new file mode 100644
index 0000000000..150a2d5fae
--- /dev/null
+++ b/challenge-133/steven-wilson/perl/ch-1.pl
@@ -0,0 +1,25 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use Test::More;
+
+my @test_input  = qw/ 10 27 85 101 /;
+my @test_output = qw/ 3 5 9 10 /;
+
+foreach my $i ( 1 .. ( scalar @test_input ) ) {
+    ok( find_isqrt( $test_input[ $i - 1 ] ) == $test_output[ $i - 1 ], "test $i" );
+}
+done_testing();
+
+sub find_isqrt {
+    my $input = shift;
+    my $x     = $input;
+    use integer;
+    my $y = ( $x + 1 ) / 2;
+    while ( $y < $x ) {
+        $x = $y;
+        $y = ( ( $x + $input / $x ) / 2 );
+    }
+    return $x;
+}