package Maths;

/**

* A number is said to be an Automorphic, if it is present in the last digit(s) of its square.

* Example- Let the number be 25, its square is 625.

* Since, 25(The input number) is present in the last two digits of its square(625),

* it is an Automorphic Number.

*/

import java.io.*;

public class AutomorphicNumber

{

//returns True if the number is a Automorphic number and False if it is not an Automorphic number

public static boolean isAutomorphic(int n)

{

int m, c, r, p, k; c = 0;

/** m = Temporary variable to store a copy of the number entered by the user.

* n = The number entered by the user

* c = Count the digits of the number entered by user.

* p = To calculate the square of the number.

* k = Support variable to count the digits of the number

*/

double s;

m = n;

p = m * m; //Calculating square of the number

do

{

k = n / 10;

c = c + 1; //Counting the digits of the number entered by user.

n = k;

}

while(n != 0);

s = Math.pow(10, c);

r = p %(int)s;

if(m == r) //Checking if the original number entered is present at the end of the square

{

return true;

}

else

{

return false;

}

}

/** Method to check if number is Automorphic Number or Not

* 1) Input - Enter a Number: 25

* Output - It is an Automorphic Number.

* 2) Input - Enter a Number: 7

* Output - It is not an Automorphic Number.

*/

public static void main(String args[]) throws IOException

{

BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

System.out.println("Enter a Number: ");

int n=Integer.parseInt(br.readLine());

if(isAutomorphic(n))

{

System.out.println("It is an Automorphic Number.");

}

else

{

System.out.println("It is not an Automorphic Number.");

}

}

}