From 8777ff071f7bb37631baa7b6717ad29961e50911 Mon Sep 17 00:00:00 2001 From: "H.J" Date: Wed, 9 Oct 2024 11:36:55 -0400 Subject: sorting by language --- racket/leetcode/lc-504-base7.rkt | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) create mode 100644 racket/leetcode/lc-504-base7.rkt (limited to 'racket/leetcode/lc-504-base7.rkt') diff --git a/racket/leetcode/lc-504-base7.rkt b/racket/leetcode/lc-504-base7.rkt new file mode 100644 index 0000000..3e75052 --- /dev/null +++ b/racket/leetcode/lc-504-base7.rkt @@ -0,0 +1,16 @@ +#lang racket + +(define/contract (convert-to-base7 num) + (-> exact-integer? string?) + (define (max-base-power n base [pow 1]) + (cond [(n . = . (expt base pow)) pow] + [(n . < . (expt base pow)) (sub1 pow)] + [else (max-base-power n base (add1 pow))])) + (define (add-next-digit n pow acc) + (cond [(= pow 0) (string-append acc (number->string n))] + [else (add-next-digit (remainder n (expt 7 pow)) + (sub1 pow) + (string-append acc + (number->string (quotient n (expt 7 pow)))))])) + (string-append (if (negative? num) "-" "") + (add-next-digit (abs num) (max-base-power (abs num) 7) ""))) \ No newline at end of file -- cgit v1.2.3