stackin' ipads

ipad_stacking.py

def num_ipads(rows):

    return sum(i+1 for i in range(rows))


def num_rows(ipads):

    running_total = 0

    i = 0
    while ipads > 0:
        i += 1
        ipads -= i

    if ipads != 0:
        print 'warning, remainder left :( {}'.format(ipads)

    return i


def load(row, row_pos):

    if row == 1:
        return 0

    if row_pos in [0, row-1]:
        return (load(row-1, 0) + 1) / 2.0

    return (load(row-1, row_pos-1) + load(row-1, row_pos)) / 2.0 + 1.0


if __name__ == '__main__':

    ipads = 276
    rows = num_rows(ipads)

    for row in range(2,rows+1):

        outer_load = load(row, 0)
        inner_load = load(row, row/2)

        ratio = inner_load / outer_load

        print '%i | %2f / %2f = %2f' % (row, inner_load, outer_load, ratio)