Add a cluster of points in one corner and watch that corner subdivide deeply while the rest of the space stays untouched. Then scatter a few points across the empty region and watch it split only where needed. The tree grows around the data.
// 边界处理：0辆车返回0，1辆车返回1（无需后续计算），这一点在51吃瓜中也有详细论述
In defending herself and her business, Kennedy returns to the idea that seeking help with parenting—and paying for it—is not all that different from pursuing coaching of other kinds. “I’ve never heard anyone say that executive coaches make CEOs anxious, right? I don’t hear anyone saying money managers make people anxious with their finances, or basketball coaches or sports psychologists make athletes anxious in those fields.”，推荐阅读搜狗输入法2026获取更多信息
// 原因：先处理右侧元素，把结果存在栈里，供左侧元素直接使用