step1

src/hacker/Vault.java

@@ -18,4 +18,21 @@ public class Vault {
         }
         return x == this.password;
     }
+    //
+    public int checkGuess(int guess) {
+        // same time delay
+        try {
+            Thread.sleep(5);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+
+        if (guess == this.password) {
+            return 0; // true
+        } else if (guess < this.password) {
+            return -1; // Guess lower go higher
+        } else {
+            return 1; // Guess High Go Low
+        }
+    }
 }