Happy Number

happy_number.java

@@ -0,0 +1,59 @@
+import java.util.*;
+class happy_number
+{
+    int y,n;
+    happy_number()
+    {
+        y=0;
+        n=0;
+    }
+    void input()
+    {
+        Scanner sc=new Scanner(System.in);
+        System.out.println("Enter the Number");
+        n=sc.nextInt();
+    }
+    int sum_of_digit(int z)
+    {
+        if(z==0)
+        {
+            return 0;
+        }
+        else
+        {
+            int d=z%10;
+            return d*d+sum_of_digit(z/10);
+        }
+    }
+
+    int happy(int x)
+    {
+        while(x>9)
+        {
+            y=sum_of_digit(x);
+            x=y;
+        }
+        return y;
+    }
+
+    void display()
+    {
+        int q=happy(n);
+        if(q==1)
+        {
+            System.out.println("Happy Number");    
+        }
+        else
+        {
+            System.out.println("Not Happy Number");
+        }
+    }
+
+    public static void main()
+    {
+        happy_number ob=new happy_number();
+        ob.input();
+        ob.display();
+    }
+}
+