Primality by trial division: Difference between revisions

Content added Content deleted

Inline

@@ Line 626: / Line 626: @@
 =={{header|Scheme}}==
+{{Works with|Scheme|R<math>^5</math>RS}}
-<lang scheme>(define (is-prime? x)
+<lang scheme>(define (prime? number)
-  (cond ((< x 2) #f)
-        ((= x 2) #t)
+  (define (*prime? divisor)
-        ((zero? (remainder x 2)) #f)
+    (or (> (* divisor divisor) number)
-        (else
+        (and (> (modulo number divisor) 0)
-          (let loop ((c 3))
+             (*prime? (+ divisor 1)))))
-            (cond ((> (* c c) x) #t)
+  (and (> number 1)
-                  ((zero? (remainder x c)) #f)
+       (*prime? 2)))</lang>
-                  (else (loop (+ c 2))))))))</lang>
 =={{header|Standard ML}}==