SPOILER for Project Euler #7

pe_7.lisp

; pe_7.lisp - Josh Sandlin - 12/28/2010
; Project Euler #7 - 10001st prime

; primality predicate function (from PCL ;)
(defun primep (number)
  (when (> number 1)
    (loop for fac from 2 to (isqrt number) never (zerop (mod number fac)))))

; array of primes
(defparameter *primes-list* (loop for i from 1 to 150000
			       when (primep i) collect i))

; solve that bad boy
(defun solve ()
  (format t "~a" (nth 10000 *primes-list*)))

; lets see how long it takes
(time (solve))

;; * (load "pe_7.lisp")
;; 104743
;; Evaluation took:
;;   0.000 seconds of real time
;;   0.000000 seconds of total run time (0.000000 user, 0.000000 system)
;;   100.00% CPU
;;   119,143 processor cycles
;;   0 bytes consed

;; T