Problem A for Qualification Round of Google Code Jam 2014

problem_a.lisp

#!/usr/bin/sbcl --script

(load "~/quicklisp/setup.lisp")
(require 'cl-ppcre)

(defun read-rows (file)
  (loop for i from 0 to 3
        collect (mapcar #'parse-integer
                        (cl-ppcre:split " " (read-line file)))))

(defun cards (rows-1 rows-2 first-row second-row)
  (intersection (elt rows-1 (1- first-row))
                           (elt rows-2 (1- second-row))))

(defun main ()
  (with-open-file
      (file (cadr *posix-argv*) :direction :input)
    (with-open-file
        (out "output" :direction :output :if-exists :supersede)
      (loop with cases = (read file)
            for case from 1 upto cases
            for first-row = (read file)
            for rows-1 = (read-rows file)
            for second-row = (read file)
            for rows-2 = (read-rows file)
            for intersection = (cards rows-1 rows-2 first-row second-row)
            do (cond
                 ((not intersection)
                  (format out "Case #~D: Volunteer cheated!~%" case))
                 ((not (cdr intersection))
                  (format out "Case #~D: ~D~%" case (car intersection)))
                 (t
                  (format out "Case #~D: Bad magician!~%" case)))))))

(main)