function y = check (arr , key, k)
  n = length(arr);
  y = true;
  
 for i=1 : k
    
    key=[key num2str(i)]  ;
    address = string2hash(key);
    address = mod(adress,n)+1;
    
    %printf(1,"key = %s -> pos = %d\n",elem,pos)
    
    if arr(adress)==0
      y=false;
    end
    
 end
end