Watch Towers

Rules

In each tower cell with one or more arrows, place a number 'x' such that each arrow points to a shaded cell x cells away in the direction of the arrow. Two arrows cannot point to the same shaded cell, and shaded cells cannot share an edge. All unshaded cells, including tower cells, must form a single connected area. There can be no shaded cells that are not pointed at by a tower cell. Tower cells cannot be shaded.

(Rules and example from WPC 2017 IB)

History of the puzzle

Invented by Dan Adams (USA) in 2017 as a submission for Puzzle Innovations Contest, a pre-event of WPC 2017.

Appearances in the past WPCs

• WPC 2017/Round 18 by Ashish Kumar