Create KeithNumber.java

Program's_Contributed_By_Contributors/Java_Programs/Misc/KeithNumber.java

@@ -0,0 +1,75 @@
+//coded by shreeyachatzz
+// Find whether a number is a Keith number
+import java.util.Scanner;
+public class KeithNumberChecker 
+{
+
+    public static void main()//Main function 
+    {
+        Scanner scanner = new Scanner(System.in);
+        System.out.print("Please enter a number: "); 
+        String n = scanner.nextLine(); 
+        // Keith numbers must be > 10
+        if (n.length() > 1 && isKeithNumber(n)) 
+        {
+            System.out.println(n + " is a Keith number!");
+        } 
+        else 
+        {
+            System.out.println(n + " is NOT a Keith number!");
+        } 
+        scanner.close(); 
+    } 
+    // Checks whether n number is a Keith number
+    public static boolean isKeithNumber(String n) 
+    {
+        int b = n.length();
+        // we keep only last n elements of the a
+        long[] a = new long[b];
+
+        for (int i = 0; i < b; i++) 
+        {
+            a[i] = Long.valueOf(n.substring(i, i + 1));
+        }
+        long next = 0;
+        long no = Long.valueOf(n);
+
+        while (next < no) 
+        {
+            next = 0;
+            for (int i = 0; i < b; i++) 
+            {
+                next += a[i];
+                if (i < b - 1) 
+                {
+                    a[i] = a[i + 1]; // shift a to left
+                } 
+                else 
+                {
+                    a[i] = next; // add new value to the a
+                }
+            }
+            if (next == no) 
+            {
+                return true;
+            }
+        }
+        return false;
+    }
+}
+/*
+(1)
+Please enter a number: 197
+197 is a Keith number!
+*//*
+(2)
+Please enter a number: 12
+12 is NOT a Keith number!
+*//*
+(3)
+Please enter a number: 14
+14 is a Keith number!
+(4)
+Please enter a number: 93993
+93993 is a Keith number!
+*/