Automorphic Number is a number whose last digits of square of the number is equal to the original number.
Example 1: 25. 252 = 625. We observe that the last two digits of 625 is 25 which is equal to the original number. Hence it is an Automorphic Number.
Example 2: 6. 62 = 36. We observe that the last digit of 36 is 6 which is equal to the original number. Hence it is an Automorphic Number.
Example 3: 12. 122 = 144. Here the last two digits of 144 is not equal to the original number. Hence it is not an Automorphic Number.
Java
import java.util.*;
public class AutomorphicNumber
{
public static void main(String args[])
{
int n=0,r=0,nCopy=0,count=0;
Scanner sc=new Scanner(System.in);
System.out.print("Enter a number: ");
n=sc.nextInt();
nCopy=n;
while(n>0)
{
count++;
n=n/10;
}
n=nCopy;
r=(n*n)%(int)Math.pow(10,count);
if(n==r)
{
System.out.println(n+" is an Automorphic Number");
}
else
{
System.out.println(n+" is not an Automorphic Number");
}
}
}