"objectiveId": "393044647133319168",
Now that we can build the tree, let's use it to search. Finding a specific point means starting at the root and asking: which child quadrant contains this coordinate? Then you recurse into that child and ask again. Each level of the tree cuts the search space by roughly three-quarters.
，这一点在safew官方版本下载中也有详细论述
BBC事實查核（BBC Verify） 對這些說法進行了核實。
// 易错点4：仅处理栈非空的情况，忽略栈空的情况 → 栈空时res[i]会是undefined
Solver and cache: content-addressable execution