dadasdas

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

int lastdigit( char *vonalkod)
{
    int t[13];
    int i;
    int elsoszam;
    int paratlan = 0;
    int paros = 0;
    int ertek;
    int pontos;
    int uj;
    for ( i = 0; i < 12; i++ )
    {
        t[i] = vonalkod[i]-'0';
    }
    for ( i = 0; i < 12; i++ )
    {
        if ( i % 2 != 0 )
        {
            paratlan = paratlan + (3*t[i]);
        }
        else
        {
            paros = paros + t[i];
        }
    }
    ertek = paros + paratlan;
    pontos = ertek % 10;
    uj = 10 - pontos;
    if (pontos == 0)
    {
        uj = 0;
    }

    return uj;
}