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;
}

Pascal :

var
a:array[1..20] of longint;
s:string;
i,x:longint;
c:integer;
begin
  readln(s);
  for i:=1 to 17 do
  val(s[i],a[i],c);
  for i:=1 to 17 do
  case i of
  1,11:a[i]:=a[i]*7;
  2,12:a[i]:=a[i]*9;
  3,13:a[i]:=a[i]*10;
  4,14:a[i]:=a[i]*5;
  5,15:a[i]:=a[i]*8;
  6,16:a[i]:=a[i]*4;
  7,17:a[i]:=a[i]*2;
  9:a[i]:=a[i]*6;
  10:a[i]:=a[i]*3;
  end;
  for i:=1 to 17 do x:=x+a[i];
  x:=x mod 11;
  case x of
  0:write(1);
  1:write(0);
  2:write('X');
  3:write(9);
  4:write(8);
  5:write(7);
  6:write(6);
  7:write(5);
  8:write(4);
  9:write(3);
  10:write(2);
  end;
end.

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]);
		
	}

}