pi.lisp

pi.lisp

(require :cl)

(defun calc-pi (n)
  (let ((in-circle 0))
    (loop for i from 1 to n do
          (let ((x (random 1.0))
                (y (random 1.0)))
            (when (< (+ (* x x) (* y y)) 1)
              (incf in-circle))))
    (* 4 (/ in-circle n))))

(defun main ()
  (format t "~A~%" (calc-pi 100000)))