The following function duck( ) is a part of some class which is used to check if a given number is…

The following function duck( ) is a part of some class which is used to check if a given number is a duck number or not. There are some places in the code marked by ?1?, ?2?, ?3? which may be replaced by a statement / expression so that the function works properly. A number is said to be Duck if the digit zero (0) is present in it.

boolean duck(int a)
{ int f=-1;
    if(a==0)
        return true;
    for(int i=a; i!=0;?1?)
    {   int c = i%10;
        if(c==?2?)
            {f=1; break; }
    }
    return (f==?3?)? false:true;
}