init

Bomb.java

@@ -0,0 +1,41 @@
+import java.io.*;
+
+public class Bomb {
+    public static final int START = 124;
+    public static final int CODE_LENGTH = 6;
+    
+    public static void defuse(String code) throws Exception {
+        if (code.length() != CODE_LENGTH) {
+            throw new Bomb.Explosion();
+        }
+
+        String curr = Integer.toHexString(CODE_LENGTH);
+        for (int i = 1; i < CODE_LENGTH; i++) {
+            curr = scramble(curr);
+            if (curr.charAt(1) != code.charAt(i)) {
+                throw new Bomb.Explosion();
+            }
+        }
+    }
+
+    private static String scramble(String secret) {
+        return Integer.toHexString(Integer.parseInt(secret, 16) * 0xA9 / 0b010011);
+    }
+
+    public static void main(String[] args) throws Exception {
+        System.out.println();
+        System.out.println("Bomb armed and ready for defusal.");
+        System.setOut(new PrintStream(new OutputStream() { public void write(int b) {} }));
+        
+        // defuse("21d74");    // TODO: Find the code, hurry!
+        defuse("000000");
+        System.setOut(SYSTEM_OUT);
+        System.out.println("Bomb defused! You saved the day!");
+        System.out.println();
+    }
+
+    public static final PrintStream SYSTEM_OUT = System.out;
+    private static class Explosion extends RuntimeException {
+        public Explosion() { super("BOOM"); }
+    }
+}