Chapter 2 · Search and order

Tell the searches apart

Use the number of windows, the discarded space, and the room architecture.

A visual reference sheet shows seven jars ordered from heavy frost to rising steam, one hand testing a central jar, and shelf panels closing around a progressively narrower range.

Picture path

  1. A hand tests the middle hot-or-cold jar and the shelf panels close around a narrower half. What search is this?Watch what disappears after one comparison: one whole side becomes impossible.
  2. Two separate frames each mark one tile on two parallel rails. How are these positions used?Each frame marks a position on its own sequence; they do not enclose one shared range.
  3. One real window frame glides along a row while its two edges keep one active region. What pattern is this?Treat the two sides as boundaries of one object, not as two independent travellers.
  4. At a numbered split landing, a comparison closes one whole staircase with a rope. Which lookup does the room encode?The value at the current landing decides which entire branch can no longer contain the target.