1 files changed, 46 insertions, 0 deletions
diff --git a/challenge-167/michael-dicicco/java/challenge167/circularprime.java b/challenge-167/michael-dicicco/java/challenge167/circularprime.java
new file mode 100644
index 0000000000..a7038ffba1
--- /dev/null
+++ b/challenge-167/michael-dicicco/java/challenge167/circularprime.java
@@ -0,0 +1,46 @@
+package challenge167;
+
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+/**
+ *
+ * @author mddicicco
+ */
+public class circularprime {
+    public static Set<String> used_numbers = new LinkedHashSet<>();
+    public static boolean isPrime(int someNumber){
+        if (someNumber <= 1){
+            return false;
+        }
+        for(int i = 2; i < (someNumber - 1); i++){
+            if (someNumber % i == 0){
+                return false;
+            }
+        }
+        return true;
+    }
+    
+    public static String rotate(String someNumber){
+        // rotate to the left one character
+        return someNumber.substring(1,someNumber.length()) + someNumber.substring(0,1);
+    }
+    
+    public static boolean validate(String someNumber){
+        // check if the original string is prime
+        if (!isPrime(Integer.parseInt(someNumber))){
+            return false;
+        }
+        
+        String temp = someNumber;
+        // check if any rotations of the string are not prime
+        for(int i = 0; i < someNumber.length() - 1; i++){
+            temp = rotate(temp);
+            if (!isPrime(Integer.parseInt(temp))){
+                return false;
+            }
+            used_numbers.add(temp);
+        }
+        return true;
+    }
+}