Data commit

Task/Prime-conspiracy/Racket/prime-conspiracy.rkt

@@ -0,0 +1,19 @@
+#lang racket
+
+(require math/number-theory)
+
+(define limit 1000000)
+
+(define table
+  (for/fold ([table (hash)] [prev 2] #:result table)
+            ([p (in-list (next-primes 2 (sub1 limit)))])
+    (define p-mod (modulo p 10))
+    (values (hash-update table (cons prev p-mod) add1 0) p-mod)))
+
+(define (pair<? p q) (or (< (car p) (car q)) (and (= (car p) (car q)) (< (cdr p) (cdr q)))))
+
+(printf "~a first primes. Transitions prime % 10 → next-prime % 10.\n" limit)
+(for ([item (sort (hash->list table) pair<? #:key car)])
+  (match-define (cons (cons x y) freq) item)
+  (printf "~a → ~a count: ~a frequency: ~a %\n"
+          x y (~a freq #:min-width 8 #:align 'right) (~r (* 100 freq (/ 1 limit)) #:precision '(= 2))))