Printing Mountain Ranges Algorithm

/\ / \ / \ /\/\ / \ /\ /\/ \ /\ / \/\ /\/\/\ for n=3 pairs of ups and downs I have 5 possible way to draw these mountains.(I should never go below the x

Solution 1:

Your problem is you are using ' ' spaces as litteral space. HTML doenst like literal spaces all that well.. Best to use   as

document.write(o.join('<br>').replace(/,\d?/g, r => '\\/' [r[1]] || '&nbsp;'));

One other thing, use a fixed-width font and proper line-height for better results.

JSFiddle Example