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Diffstat (limited to 'racket/leetcode/lc-745-prefix-suffix.rkt')
| -rw-r--r-- | racket/leetcode/lc-745-prefix-suffix.rkt | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/racket/leetcode/lc-745-prefix-suffix.rkt b/racket/leetcode/lc-745-prefix-suffix.rkt new file mode 100644 index 0000000..b01e3bb --- /dev/null +++ b/racket/leetcode/lc-745-prefix-suffix.rkt @@ -0,0 +1,27 @@ +#lang racket +(define word-filter% + (class object% + (super-new) + + ; words : (listof string?) + (init-field + words) ; Take in the provided dictionary. + (define word-ends-hash (make-hash)) ; Make an empty hash table. + + (for/list ([w (in-list words)] ; For each word in the dictionary, + [index (in-naturals)]) ; and its corresponding index, + (define len (string-length w)) ; calculate its length, + (for*/list ([head (in-range 1 (min 11 (add1 len)))] ; and for every combination of head length + [tail (in-range 1 (min 11 (add1 len)))]) ; and tail length + (hash-set! word-ends-hash ; from 1 to the max. affix length, + (list (substring w 0 head) ; set the key to the list containing + (substring w (- len tail) len)) ; the prefix and suffix + index))) ; and map it to the word's index. + + ; f : string? string? -> exact-integer? + (define/public (f prefix suffix) ; Return the mapped value for the affixes + (hash-ref word-ends-hash (list prefix suffix) -1)))) ; or -1 if it doesn't exist. + +;; Your word-filter% object will be instantiated and called as such: +;; (define obj (new word-filter% [words words])) +;; (define param_1 (send obj f prefix suffix))
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