1 files changed, 32 insertions(+), 32 deletions(-)

M client.rkt

@@ 99,41 99,41 @@
                     (λ ([s : String]) : Integer
                        (let ([entry (assert (string->number s)
                                             exact-integer?)])
-                         (if (and (>= entry 1) (<= entry num-cands))
-                             (sub1 entry)
-                             (raise-user-error
-                              (format "every entry in your ballot should be a valid integer ∈ [~a,~a]"
-                                      1 num-cands)))))
+                         (when (or (< entry 1) (> entry num-cands))
+                           (raise-user-error
+                            (format "every entry in your ballot should be a valid integer ∈ [~a,~a]"
+                                    1 num-cands)))
+                         (sub1 entry)))
                     (string-split
                      (readline
                       "Rank the candidates (most to least preferable): ")))])
-             (if (members-unique? entries)
-                 (let* ([m num-cands]
-                        [n m]
-                        [arr (array->mutable-array
-                              (make-array (vector m n) 0))]
-                        [num-peers (cast (length peer-inputs) Positive-Integer)])
-                   (let loop ([entry (car entries)]
-                              [rst (cdr entries)])
-                     (for ([other rst])
-                       (when (< entry other)
-                         (array-set! arr (vector entry other) 1)))
-                     (when (not (empty? rst))
-                       (loop (car rst) (cdr rst))))
-                   (bytes->integer
-                    (for*/fold : Bytes
-                       ([bstr : Bytes #""])
-                       ([i : Natural (in-range m)]
-                        [j : Natural (in-range n)]
-                        #:when (< i j))
-                     (bytes-append bstr
-                                   (integer->bytes
-                                    (array-ref arr (vector i j))
-                                    (cast (min (integer-bytes-length num-peers #t) 1)
-                                          Positive-Integer)
-                                    #t)))
-                    #t))
-                 (raise-user-error "every entry in your ballot must be unique"))))))
+             (when (not (members-unique? entries))
+               (raise-user-error "every entry in your ballot must be unique"))
+             (let* ([m num-cands]
+                    [n m]
+                    [arr (array->mutable-array
+                          (make-array (vector m n) 0))]
+                    [num-peers (cast (length peer-inputs) Positive-Integer)])
+               (let loop ([entry (car entries)]
+                          [rst (cdr entries)]
+                          [remaining (set-remove (list->set (range num-cands))
+                                                 (car entries))])
+                 (for ([other remaining])
+                   (array-set! arr (vector entry other) 1))
+                 (when (not (empty? rst))
+                   (loop (car rst) (cdr rst) (set-remove remaining (car rst)))))
+               (bytes->integer
+                (for*/fold : Bytes
+                    ([bstr : Bytes #""])
+                    ([i : Natural (in-range m)]
+                     [j : Natural (in-range n)])
+                  (bytes-append bstr
+                                (integer->bytes
+                                 (array-ref arr (vector i j))
+                                 (cast (min (integer-bytes-length num-peers #t) 1)
+                                       Positive-Integer)
+                                 #t)))
+                #t))))))
 
   (define poly (random-poly
                 (cast (sub1 (length peer-inputs)) Natural)