結果

問題 No.91 赤、緑、青の石
ユーザー norioc
提出日時 2025-07-10 00:47:41
言語 Scheme
(Gauche-0.9.15)
結果
AC  
実行時間 182 ms / 5,000 ms
コード長 4,349 bytes
コンパイル時間 209 ms
コンパイル使用メモリ 7,972 KB
実行使用メモリ 29,184 KB
最終ジャッジ日時 2025-07-10 00:47:49
合計ジャッジ時間 7,998 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge3
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ファイルパターン 結果
sample AC * 4
other AC * 28
権限があれば一括ダウンロードができます

ソースコード

diff # 

(use srfi.13)  ; string
(use srfi.42)  ; list-ec
(use srfi.197) ; chain
(use gauche.collection)
(use gauche.dictionary)
(use gauche.generator)
(use gauche.sequence)
(use scheme.list)
(use scheme.set)
(use util.combinations)
(use util.match)

(define input read-line)

(define (ii)
  (string->number (read-line)))

(define (li)
  (let ((s (read-line)))
    (map string->number (string-split s " "))))

(define (prn . args)
  (for-each-with-index (lambda (i x)
                         (when (> i 0)
                           (display " "))
                         (display x))
                       args)
  (newline))

(define prn* (pa$ apply prn))

(define int string->number)
(define str x->string)

(define-method min ((xs <sequence>))
  (fold min (~ xs 0) xs))
(define-method max ((xs <sequence>))
  (fold max (~ xs 0) xs))

(define (minmax . xs)
  (values->list (apply min&max xs)))
(define-method minmax ((xs <sequence>))
  (values->list (apply min&max xs)))

(define (sum xs)
  (fold + 0 xs))

(define (divmod a b)
  (values->list (div-and-mod a b)))

(define (1+ n) (+ n 1))
(define (1- n) (- n 1))
(define (!= a b) (not (= a b)))
(define (midpoint a b) (div (+ a b) 2))

(define pow
  (case-lambda
   ((a b) (expt a b))
   ((a b m) (expt-mod a b m))))

(define gcd* (apply$ gcd))
(define isqrt exact-integer-sqrt)

(define ++ string-append)

(define zip (map$ list))
(define all every)

(define (pairwise xs)
  (zip xs (cdr xs)))

(define (comb n k)
  (if (or (< k 0) (> k n))
      0
      (let loop ((i 0)
                 (x 1))
        (if (= i k)
            x
            (loop (1+ i) (div (* x (- n i)) (1+ i)))))))

(define (make-dict)
  (make-hash-table equal-comparator))

(define-method frequencies ((xs <sequence>))
  (rlet1 dict (make-dict)
    (for-each (^x (dict-update! dict x 1+ 0))
              xs)))

(define (yn b)
  (prn (if b "Yes" "No")))

(define-macro (input! bindings . body)
  (let loop ((bs (reverse bindings))
             (res '()))
    (if (null? bs)
        `(let*-values ,res
           ,@body)
        (cond
         ((symbol? (car bs))
          (loop (cdr bs)
                (cons `((,(car bs)) (values (ii)))
                      res)))
         ((list? (car bs))
          (loop (cdr bs)
                (cons `(,(car bs) (apply values (li)))
                      res)))
         (else
          'error)))))

(define mlet match-let)
(define mlet* match-let*)
(define mlet1 match-let1)

(define-macro (mfn pat . body)
  (let ((arg (gensym)))
    `(lambda (,arg)
       (mlet1 ,pat ,arg
         ,@body))))

(define-syntax count-ec
  (syntax-rules ()
    ((_ qualifiers ...)
     (sum-ec qualifiers ... 1))))

(define-method len ((xs <list>))
  (length xs))
(define-method len ((s <string>))
  (string-length s))
(define-method len ((vs <vector>))
  (vector-length vs))

(define (accum xs)
  (define (proc a b)
    (let1 t (+ a b)
      (values t t)))
  (map-accum proc 0 xs))

(define (digits n)
  (map digit->integer (str n)))

(define (digits->int ds)
  (fold-left (^(a b) (+ (* 10 a) b)) 0 ds))

(define (-> x . fns)
  (call-with-values (^() (values x))
    (apply compose (reverse fns))))

(define (rep n thunk)
  (list-tabulate n (^i (thunk))))

(define (zip-longest . args)
  (let* ((n (apply max (map length args)))
         (xxs (map (^(xs)
                     (append xs (make-list (- n (length xs)) #f)))
                   args)))
    (map (pa$ delete #f)
         (apply zip xxs))))

(define (set-from xs)
  (apply set eqv-comparator xs))

(define (difference xs ys)
  (let ((excludes (set-from ys)))
    (filter (^x (not (set-contains? excludes x))) xs)))

(define (bsearch low high pred :key (complement? #f))
  (define satisfy? (if complement?
                       (complement pred)
                       pred))

  (assume (satisfy? low))

  (let loop ((lo low)
             (hi high)
             (res low))
    (cond
     ((<= lo hi)
      (let1 m (div (+ lo hi) 2)
        (if (satisfy? m)
            (loop (1+ m) hi (max res m))
            (loop lo (1- m) res))))
     (else
      (if complement?
          (1+ res)
          res)))))

(input! ((R G B))
  (define (can? n)
    (chain
     (sum-ec (: x (map (cut - <> n) (list R G B)))
             (if (> x 0)
                 (div x 2)
                 x))
     (>= _ 0)))

  (->
   (bsearch 0 (max R G B) can?)
   prn))
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