seed.js

We now have a bit of work to do here. First change both hor and ver:

function hor(n,sn) {
  ...
        set_a_sn(r0+1,c0+i,v,sn);
  ...
function ver(n,sn) {
  ...
        set_a_sn(r0+i,c0+1,v,sn);
  ...

and finally ...

seed()
function seed() {
  ver(4,8);
  hor(4,7);
  ver(3,6);
  hor(3,5);
  ver(2,4);
  hor(2,3);
  ver(1,2);
  hor(1,1);
}

Now everything is in place. All we have to do is write a check function that will scan the whole grid to ascertain which ships are complete.

As usual have a go yourself first. The only line you may need help with is this one:

      el.style.opacity=1;