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Ingy döt Net 2013-06-05 21:47:54 +00:00
parent 1f1ad49427
commit 6f050a029e
2496 changed files with 37609 additions and 3031 deletions
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14
Task/Parsing-RPN-calculator-algorithm/Racket/parsing-rpn-calculator-algorithm-1.rkt Normal file
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#lang racket
(define (calculate-RPN expr)
(for/fold ([stack '()]) ([token expr])
(printf "~a\t -> ~a~N" token stack)
(match* (token stack)
[((? number? n) s) (cons n s)]
[('+ (list x y s ___)) (cons (+ x y) s)]
[('- (list x y s ___)) (cons (- y x) s)]
[('* (list x y s ___)) (cons (* x y) s)]
[('/ (list x y s ___)) (cons (/ y x) s)]
[('^ (list x y s ___)) (cons (expt y x) s)]
[(x s) (error "calculate-RPN: Cannot calculate the expression:"
(reverse (cons x s)))])))

1
Task/Parsing-RPN-calculator-algorithm/Racket/parsing-rpn-calculator-algorithm-2.rkt Normal file
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(calculate-RPN (in-port read (open-input-string "3.0 4 2 * 1 5 - 2 3 ^ ^ / +")))