void unref(void *x) {
思路：单调递减栈，找「上一个比当前价格大的元素索引」。正序遍历，弹出所有 ≤ 当前价格的索引；跨度 = 当前索引 - 栈顶索引（栈空则为 当前索引 + 1）。
。关于这个话题，服务器推荐提供了深入分析
const reader = stream.getReader({ mode: 'byob' });
To make it happen, he needed to build four powerful legs for the so-called At-At – which famously first appeared in The Empire Strikes Back – that he could control with some precision.