void*wrap_malloc(unsigned long long n) { return malloc(n); }
// 易错点5：忘记push当前索引 → 后续价格无法找到正确的上一个更大值，结果全错，这一点在91视频中也有详细论述
第六十一条 本法下列用语的含义：，详情可参考谷歌浏览器【最新下载地址】
Delete a checkpoint，这一点在下载安装 谷歌浏览器 开启极速安全的 上网之旅。中也有详细论述
The algorithm also visits children in order of distance to the query point. This means it checks the most promising quadrants first, which tends to find a good candidate early and enables aggressive pruning of the remaining quadrants. Without this ordering, the algorithm would still produce the correct result, but it would prune fewer nodes.