artificial intelligence:write a program to play Connect Four

connect-four-naive (1) (3).rkt

#lang racket (require json racket/os) ;;; (valid-moves precept) -> (listof exact-nonnegative-integer?) ;;; percept : jsexpr? ;;; Returns a list of the valid moves - that is columns that aren't full. (define (valid-moves precept) (match precept ((hash-table ('player player) ('height height) ('width width) ('grid grid)) (for/fold ((moves '())) ((col (in-list grid)) (i (in-naturals))) (cond ((= 0 (first col)) (append moves (list i))) (else moves)))))) ;;; (main) -> void? (define (main) (displayln "Connect Four" (current-error-port)) ;; Seed the current pseudo-random number generator with a value that will be ;; different for different player programs (random-seed (modulo (abs (* (getpid) (current-milliseconds))) (sub1 (expt 2 31)))) ;; Process the precepts. (for ((json (in-lines))) (displayln json (current-error-port)) (with-handlers ((exn:fail? (lambda (e) (displayln "null")))) (define precept (string->jsexpr json)) ;; Find the valid moves. (define moves (valid-moves precept)) ;; Choose one at random. (define move (list-ref moves (random (length moves)))) ;; Return the action. (define action (hasheq 'move move)) (define action-json (jsexpr->string action)) (displayln action-json (current-error-port)) (displayln action-json) (flush-output)))) ;;; Start the program. (main)