Arrows
Background
This puzzle was invented by Erich Friedmann.
Puzzle and Goal
An unsolved puzzle is a rectangular grid. In each cell is a number and an arrow.
The goal is to color the arrows according to the rules.
Rules
The solved grid must satisfy the following conditions:
A white arrow points to N white arrows, where N is the number inside the arrow.
A black arrow points to some number of white arrows other than N.
Other Names
Scheinwerfer; Spotlight
Playable Online