From 8ab65dc2da1742eb86ec636c50c7018385b68167 Mon Sep 17 00:00:00 2001 From: "J.J" Date: Thu, 30 Nov 2023 17:10:00 -0500 Subject: prep for 2023, renaming for consistency --- 2019/day-04/day-04.rkt | 39 --------------------------------------- 1 file changed, 39 deletions(-) delete mode 100644 2019/day-04/day-04.rkt (limited to '2019/day-04') diff --git a/2019/day-04/day-04.rkt b/2019/day-04/day-04.rkt deleted file mode 100644 index 9518779..0000000 --- a/2019/day-04/day-04.rkt +++ /dev/null @@ -1,39 +0,0 @@ -#lang racket - -(define (number->digits n [acc '()]) - (cond - [(< n 10) (cons n acc)] - [else (number->digits (quotient n 10) (cons (remainder n 10) acc))])) - -(define (always-increasing? xs) - (match xs - [(list _) #t] - [(list* a b _) #:when (<= a b) (always-increasing? (cdr xs))] - [_ #f])) - -(define (adjacent-pair? xs) - (match xs - [(list _) #f] - [(list* a a _) a] - [_ (adjacent-pair? (cdr xs))])) - -;; part 1 -(for/sum ([password (inclusive-range 125730 579381)] - #:do [(define digits (number->digits password))] - #:when ((conjoin always-increasing? adjacent-pair?) digits)) - 1) - -;; part 2 -(define (not-in-adjacent-triplet? xs) - (match xs - [(list a a c _ _ _) #:when (not (= a c)) #t] - [(list b a a c _ _) #:when (not (or (= a b) (= a c))) #t] - [(list _ b a a c _) #:when (not (or (= a b) (= a c))) #t] - [(list _ _ b a a c) #:when (not (or (= a b) (= a c))) #t] - [(list _ _ _ b a a) #:when (not (= a b)) #t] - [_ #f])) - -(for/sum ([password (inclusive-range 125730 579381)] - #:do [(define digits (number->digits password))] - #:when ((conjoin always-increasing? adjacent-pair? not-in-adjacent-triplet?) digits)) - 1) \ No newline at end of file -- cgit v1.2.3