Logic Masters Deutschland e.V.

According to the following rules, place the black "triangles forming a square" in the grid.
1. You can place four kinds of black triangles in the square.
2. You cannot place black triangles in black squares.
3. The part of the grid that is still white (not covered by black triangles) always forms a rectangle or square.
4. The numbers indicate how many black triangles there are around vertically and horizontally.

For more detailed rule legends, please refer to: https://www.nikoli.co.jp/en/puzzles/shakashaka.html

Author: 红葉 (MOMIJI), from China, this question comes from his personal blog.

PZV link

If you like this type of puzzle, you can go to this website to do more, https://www.janko.at/Raetsel/Shakashaka/index.htm