Initial data commit

Task/Primality-by-Wilsons-theorem/Java/primality-by-wilsons-theorem.java

@@ -0,0 +1,30 @@
+import java.math.BigInteger;
+
+public class PrimaltyByWilsonsTheorem {
+
+    public static void main(String[] args) {
+        System.out.printf("Primes less than 100 testing by Wilson's Theorem%n");
+        for ( int i = 0 ; i <= 100 ; i++ ) {
+            if ( isPrime(i) ) {
+                System.out.printf("%d ", i);
+            }
+        }
+    }
+
+
+    private static boolean isPrime(long p) {
+        if ( p <= 1) {
+            return false;
+        }
+        return fact(p-1).add(BigInteger.ONE).mod(BigInteger.valueOf(p)).compareTo(BigInteger.ZERO) == 0;
+    }
+
+    private static BigInteger fact(long n) {
+        BigInteger fact = BigInteger.ONE;
+        for ( int i = 2 ; i <= n ; i++ ) {
+            fact = fact.multiply(BigInteger.valueOf(i));
+        }
+        return fact;
+    }
+
+}