← Range ArcadeWORLD Nº 019 · SORT BY THE LOW BITS
📮 milestone postEVERY PARCEL KNOWS ITS CART

TEN WAVES. FIVE CARTS. ONE RULE.

The address
is the arithmetic.

A parcel for milestone 8,191 goes on the hall cart, because 8,192 is 2¹³.
Read the low bits of g+1 and the cart is obvious.

THE SORTING ROOMWAVE 0 / 10
📮

Small buildings at small milestones,
big halls at the biggest.

Every parcel is addressed to a milestone on the road. Huts stand at small round numbers, cottages at bigger ones, farmsteads and halls at the biggest.
Drag the cart token onto the parcel. Easy and medium shifts show the address in binary. Nothing standing there? Return to sender.

$0 · SERVED 0DRAG THE CART TOKEN ONTO A PARCEL · NO BUILDING THERE? RETURN TO SENDERSECOND CLASS

rankOf(g) is v2(g+1) against the ranks 4, 7, 10, 13: a count of trailing zeros, no lookup.

ANOTHER SACK OF PARCELS

Words choose which milestones come down the belt.

SORTING NOTES

Count the trailing zeros.

A settlement of rank k stands at milestone g when 2^k divides g+1: huts at k=4, cottages 7, farmsteads 10, halls 13. So a parcel's cart is the number of trailing zero bits of g+1, and fewer than four means nobody lives there: return to sender.

Drag a cart token onto the parcel. A wrong cart costs the parcel patience and comes back to you. Easy shifts print the binary on the label; harder shifts do not.

Each sorted parcel pays by its rank. Three parcels falling off the belt in one wave closes the room; ten waves, or a hundred dollars, wins.

THE SHIFT IS OVER

📮

Every order,
every wave.

A LITTLE SORTING ROOM FOR A FRIEND

Sort the post with me.