1 files changed, 45 insertions, 0 deletions
diff --git a/Java/Beginer training/src/VampireNumber.java b/Java/Beginer training/src/VampireNumber.java
new file mode 100644
index 0000000..63d7085
--- /dev/null
+++ b/Java/Beginer training/src/VampireNumber.java
@@ -0,0 +1,45 @@
+public class VampireNumber {
+    public static void main(String args[]){
+        //NOTE: Works ONLY with 4 digit numbers, for bigger use BigVampireNumber
+        System.out.println(FindVampireNumber(6880));
+    }
+
+     public static String FindVampireNumber(int result){
+        String num = result + "";
+        int first = num.charAt(0) - 48, second = num.charAt(1) - 48, third = num.charAt(2) - 48, fourth = num.charAt(3) - 48;
+
+        for (int i = 0; i < 4; i++){
+            for (int j = 0; j < 3; j++){
+                int first_half = Combine(first, second), second_half = Combine(third, fourth);
+                int swapped_first_half = Combine(first, fourth), swapped_second_half = Combine(third, second);
+
+                if (first_half * second_half == result) {
+                    return result + " = " + first_half + " * " + second_half;
+                }
+                else if (swapped_first_half *swapped_second_half == result){
+                    return result + " = " + swapped_first_half + " * " + swapped_second_half;
+                }
+
+                switch (j) {
+                    case 0:
+                    case 1:
+                    int temp = fourth;
+                        fourth = second; second = temp;
+                        temp = third;
+                        third = fourth; fourth = temp;
+
+                        break;
+                    case 2:
+                        temp = second;
+                        second = first; first = temp;
+                        break;
+                }
+            }
+        }
+        return result + " isn't a vampire number";
+    }
+
+    private static int Combine(int first, int second) {
+        return (first * 10) + second;
+    }
+}