1. 前置环境要求 (Prerequisites)
Number (3): Everything in this space must add up to 3. The answer is 2-2, placed vertically; 1-0, placed vertically.，这一点在搜狗输入法2026中也有详细论述
其中白色是广角像素、蓝色是窄角像素，转动屏幕，窄角像素就看不见了。，详情可参考搜狗输入法2026
Regions with many nearby points keep subdividing. Regions with few or no points stay large. The tree adapts to the data: dense areas get fine-grained cells, sparse areas stay coarse. The split grid is predetermined (always at midpoints), but the tree only refines cells that need it. Sparse regions stay as single large nodes while dense regions subdivide deeply.