PRIME1 - SPOJ 2. Prime Generator
Peter wants to generate some prime numbers for his cryptosystem. Help him! Your task is to generate all prime numbers between two given numbers!
Input
The input begins with the number t of test cases in a single line (t<=10). In each of the next t lines there are two numbers m and n (1 <= m <= n <= 1000000000, n-m<=100000) separated by a space.
Output
For every test case print all prime numbers p such that m <= p <= n, one number per line, test cases separated by an empty line.
Example
Input: 2 1 10 3 5 Output: 2 3 5 7 3 5Warning: large Input/Output data, be careful with certain languages (though most should be OK if the algorithm is well designed)
LISP SBCL
可惜 TLE 了。先了解一下語言,以后再優(yōu)化。
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(defun primep(n)
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(when (< n 2) (return-from primep NIL))
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(when (= n 2) (return-from primep T))
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(let ((m (floor (sqrt n))) (i 2))
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(loop
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(when (> i m) (return-from primep T))
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(when (zerop (rem n i)) (return-from primep NIL))
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(incf i))))
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(defun solve(m n)
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(do ((p m (1+ p)))
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((> p n))
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(when (primep p) (format t "~d~%" p)))
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(format t "~%"))
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(let ((cnt (parse-integer (read-line)))
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m n lin)
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(dotimes (i cnt)
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(setf lin (read-line))
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(setf m (parse-integer (subseq lin 0 (position #\Space lin))))
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(setf n (parse-integer (subseq lin (1+ (position #\Space lin)))))
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(solve m n)))
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新版本,還是 TLE。
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(defconstant +max-size+ 35000)
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(defvar *prime* (make-array +max-size+ :initial-element t))
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(defvar *prime-size* 0)
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(defun init-prime()
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(do
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((i 2 (1+ i)))
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((>= i +max-size+))
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(when (elt *prime* i)
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(setf (elt *prime* *prime-size*) i)
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(incf *prime-size*)
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(do
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((j (+ i i) (+ j i)))
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((>= j +max-size+))
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(setf (elt *prime* j) nil)))))
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(defun primep(n)
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(when (< n 2) (return-from primep nil))
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(when (or (= n 2) (= n 3)) (return-from primep t))
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(do
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((i 0 (1+ i))
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(p (elt *prime* 0) (elt *prime* (1+ i))))
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((or (>= i *prime-size*) (> (* p p) n)) t)
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(when (zerop (rem n p)) (return-from primep nil))))
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(defun solve(m n)
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(do ((p m (1+ p)))
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((> p n))
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(when (primep p) (format t "~d~%" p)))
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(format t "~%"))
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(init-prime)
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(let ((cnt (parse-integer (read-line)))
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m n lin)
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(dotimes (i cnt)
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(setf lin (read-line))
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(setf m (parse-integer (subseq lin 0 (position #\Space lin))))
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(setf n (parse-integer (subseq lin (1+ (position #\Space lin)))))
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(solve m n)))
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posted on 2012-02-05 17:19 coreBugZJ 閱讀(324) 評論(0) 編輯 收藏 引用 所屬分類: ACM 、Lisp