Data commit

Task/Circular-primes/Sidef/circular-primes.sidef

@@ -0,0 +1,29 @@
+func is_circular_prime(n) {
+    n.is_prime || return false
+
+    var circular = n.digits
+    circular.min < circular.tail && return false
+
+    for k in (1 ..^ circular.len) {
+        with (circular.rotate(k).digits2num) {|p|
+            (p.is_prime && (p >= n)) || return false
+        }
+    }
+
+    return true
+}
+
+say "The first 19 circular primes are:"
+say 19.by(is_circular_prime)
+
+say "\nThe next 4 circular primes, in repunit format, are:"
+{|n| (10**n - 1)/9 -> is_prob_prime }.first(4, 4..Inf).each {|n|
+    say "R(#{n})"
+}
+
+say "\nRepunit testing:"
+[5003, 9887, 15073, 25031, 35317, 49081].each {|n|
+    var now = Time.micro
+    say ("R(#{n}) -> ", is_prob_prime((10**n - 1)/9) ? 'probably prime' : 'composite',
+        " (took: #{'%.3f' % Time.micro-now} sec)")
+}