C++ :

#include<iostream>
using namespace std;
int main()
{
	int weight[17]={7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2};
	string map="10X98765432";
	int i,sum=0;
	string s;
	cin>>s;
	for(i=0;i<17;i++)
	{
		sum+=(s[i]-'0')*weight[i];
	}
	cout<<map[sum%11];
	return 0;
}

Java :

import java.util.*;
public class Main {
	public static void main(String[] args) {
		Scanner input=new Scanner(System.in);
		int sum=0;
		String str=input.nextLine();
		int l=str.length();
		int a[]=new int[l];
		int b[]= {7 ,9 ,10, 5, 8 ,4, 2 ,1, 6 ,3 ,7 ,9, 10, 5 ,8, 4, 2};
		String c[]= {"1","0","X","9","8","7","6","5","4","3","2" };
		for(int i=0;i<l;i++) {
			a[i]=Integer.parseInt(str.substring(i, i+1));
			sum+=a[i]*b[i];
		}
		int yu=sum%11;
		
			System.out.print(c[yu]);
		
	}

}