Sample

Progressing

Rules

1. Place light bulbs (circles) according to the following rules.
2. Light bulbs are permitted to place at any white squares. But a number indicates how many light bulbs are next to it, vertically and horizontally.
3. Each light bulb illuminates from bulb to black square or outer frame in
its row and column.
4. Every white squares must be illuminated and every light bulbs should not illuminate each other.

Features

Solution