diff options
Diffstat (limited to 'leetcode/lc-953-alien-dictionary.rkt')
| -rw-r--r-- | leetcode/lc-953-alien-dictionary.rkt | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/leetcode/lc-953-alien-dictionary.rkt b/leetcode/lc-953-alien-dictionary.rkt new file mode 100644 index 0000000..f72a895 --- /dev/null +++ b/leetcode/lc-953-alien-dictionary.rkt @@ -0,0 +1,26 @@ +#lang racket + +(define/contract (is-alien-sorted words order) + (-> (listof string?) string? boolean?) + (define alpha-order + (make-hash (map (λ (a b) (cons a b)) + (map string (string->list order)) + (build-list (string-length order) identity)))) + (hash-set! alpha-order #\* -1) + (define (alien<? s1 s2) + (cond [(equal? s1 "") #true] + [(equal? s2 "") #false] + [(equal? (hash-ref alpha-order (substring s1 0 1)) + (hash-ref alpha-order (substring s2 0 1))) + (alien<? (substring s1 1 (string-length s1)) + (substring s2 1 (string-length s2)))] + [(< (hash-ref alpha-order (substring s1 0 1)) + (hash-ref alpha-order (substring s2 0 1))) #true] + [else false])) + (equal? words + (sort words alien<?))) + +(is-alien-sorted '["hello" "leetcode"] "hlabcdefgijkmnopqrstuvwxyz") +(is-alien-sorted '["word" "world" "row"] "worldabcefghijkmnpqstuvxyz") +(is-alien-sorted '["apple" "app"] "abcdefghijklmnopqrstuvwxyz") +(is-alien-sorted '["iekm" "tpnhnbe"] "loxbzapnmstkhijfcuqdewyvrg")
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