FirstFT: the day's biggest stories
另一个现实背景是：今日头条的体量早已不再增长。在短视频的长期分流下，纯资讯类产品的上限越来越清晰。与其在一个天花板已经出现的产品上继续加码，不如把长内容放进抖音，用更大的流量池重新分配注意力。
，更多细节参见夫子
I learned that for 4-SAT, if clause to variable ratio is more than 10, the generated problems become difficult to solve, and the likelihood of formula to be SAT or UNSAT is close to 50%. So I generated 3 types of formulas:
Flight controllers at Nasa working out how to get the crippled Apollo 13 back to Earth.
The tree starts as a single region covering the whole space. As points arrive, they get dropped into the region that contains them. When a region exceeds its capacity (the maximum number of points it can hold before splitting), the region divides into four children, and the existing points get redistributed.