C :

#include<stdio.h>
int main(){
	int x,n;
	int sum;
	scanf("%d %d",&x,&n);
	while(n--){
		sum=0;
		while(x!=0){
		int t=x%10;
		sum+=t*t;
		x/=10;

		}
		x=sum;
	}
	printf("%d",sum);
}

C++ :

#include <iostream>
using namespace std;
int a[100];
void f(int n,int m)
{if(m==0) {
cout<<n<<endl;
return;
}
int i,sum=0;
for(i=0;n%10;i++)
{a[i]=n%10;n/=10;
}
for(--i;i>=0;i--)
sum+=a[i]*a[i];
f(sum,m-1);
}
int main()
{int n,m;
cin>>n>>m;
f(n,m);
	return 0;
}

Java :

import java.util.Scanner;



public class Main {

	public static void main(String[] args) {
		int x,n;
		Scanner sc=new Scanner(System.in);
		x=sc.nextInt();
		n=sc.nextInt();
		int sum=x;
		while(n-- != 0)
		{
			int t=sum;
			sum=0;
			while(t > 0)
			{
				sum=sum+(t%10)*(t%10);
				t/=10;
			}
		}
		System.out.println(sum);
	}

}