From 989114a87a416f86cb62e1de98ed78ddbab60bad Mon Sep 17 00:00:00 2001 From: Mistivia Date: Tue, 6 Feb 2024 15:24:03 +0800 Subject: solve codewars 7-kyu a rule of divisibiliy by 7 --- codewars/7-kyu/a-rule-of-divisibility-by-7/solution.rkt | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 codewars/7-kyu/a-rule-of-divisibility-by-7/solution.rkt diff --git a/codewars/7-kyu/a-rule-of-divisibility-by-7/solution.rkt b/codewars/7-kyu/a-rule-of-divisibility-by-7/solution.rkt new file mode 100644 index 0000000..6859107 --- /dev/null +++ b/codewars/7-kyu/a-rule-of-divisibility-by-7/solution.rkt @@ -0,0 +1,15 @@ +#lang racket + +;; https://www.codewars.com/kata/55e6f5e58f7817808e00002e + +(provide seven) + +(define (seven m) + (define (impl cur steps) + (define x (quotient cur 10)) + (define y (modulo cur 10)) + (define next (- x (* 2 y))) + (if (< cur 100) + (cons cur steps) + (impl next (+ 1 steps)))) + (impl m 0)) -- cgit v1.0