Question

Suppose I have some serially numbered items that are 1-n units wide, that need to be displayed in rows. Each row is m units wide. I need some pseudo-code that will output the rows, for me, so that the m-width limit is kept. This is not a knapsack problem, as the items must remain in serial number order – empty spaces at the end of rows are fine.

I’ve been chasing my tail over this, partly because I need it in both PHP and jQuery/javascript, hence the request for pseudo-code….

Answer 1

while (!items.isEmpty()) {
  rowRemain = m;
  rowContents = [];
  while (!items.isEmpty() && rowRemain > items[0].width) {
    i = items.shift();
    rowRemain -= i.width
    rowContents.push(i);
  }
  rows.push(rowContents);
}

Running time is Θ(number of items)