1 files changed, 30 insertions, 0 deletions
diff --git a/challenge-305/deadmarshal/java/Ch1.java b/challenge-305/deadmarshal/java/Ch1.java
new file mode 100644
index 0000000000..31a92f703c
--- /dev/null
+++ b/challenge-305/deadmarshal/java/Ch1.java
@@ -0,0 +1,30 @@
+import java.util.ArrayList;
+import java.util.List;
+
+public class Ch1 {
+  public static void main(String[] args) {
+    System.out.println(binary_prefix(new int[]{1, 0, 1}));
+    System.out.println(binary_prefix(new int[]{1, 1, 0}));
+    System.out.println(binary_prefix(
+      new int[]{1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1}));
+  }
+
+  private static boolean is_prime(int n) {
+    if (n <= 1) return false;
+    if ((n == 2) || (n == 3)) return true;
+    if ((n % 2 == 0) || (n % 3 == 0)) return false;
+    for (int i = 5; i < Math.sqrt(n); i += 6)
+      if ((n % i == 0) || (n % (i + 2) == 0)) return false;
+    return true;
+  }
+
+  private static List<Boolean> binary_prefix(int[] arr) {
+    StringBuilder sb = new StringBuilder();
+    List<Boolean> ret = new ArrayList<>();
+    for (int i = 0; i < arr.length; ++i) {
+      sb.append(arr[i]);
+      ret.add(is_prime(Integer.parseInt(sb.toString(), 2)));
+    }
+    return ret;
+  }
+}