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-228-summary-ranges.rkt | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 racket/leetcode/lc-228-summary-ranges.rkt (limited to 'racket/leetcode/lc-228-summary-ranges.rkt') diff --git a/racket/leetcode/lc-228-summary-ranges.rkt b/racket/leetcode/lc-228-summary-ranges.rkt new file mode 100644 index 0000000..9140895 --- /dev/null +++ b/racket/leetcode/lc-228-summary-ranges.rkt @@ -0,0 +1,27 @@ +#lang racket +(define (summary-ranges nums) + (define range-pairs + (cond + [(empty? nums) '()] + [(empty? (cdr nums)) (list (cons (car nums) (car nums)))] + [else (for/fold ([ranges '()] + [open-pair (first nums)] + [prev-num (first nums)] + #:result (append ranges (list (cons open-pair prev-num)))) + ([i (cdr nums)]) + (cond [(= (add1 prev-num) i) + (values ranges + open-pair + i)] + [else + (values (append ranges (list (cons open-pair prev-num))) + i + i)]))])) + (for/list ([p (in-list range-pairs)]) + (cond [(= (car p) (cdr p)) (format "~a" (car p))] + [else (format "~a->~a" (car p) (cdr p))]))) + +(summary-ranges '(0 1 2 4 5 7)) +(summary-ranges '(0 2 3 4 6 8 9)) +(summary-ranges '()) +(summary-ranges '(0)) \ No newline at end of file -- cgit v1.2.3