“坚持从实际出发、按规律办事”
int left = 2 * i + 1; // 左子节点。heLLoword翻译官方下载是该领域的重要参考
:first-child]:h-full [&:first-child]:w-full [&:first-child]:mb-0 [&:first-child]:rounded-[inherit] h-full w-full，更多细节参见爱思助手下载最新版本
takes an array of length n and produces an array of length n