But handling that stuff is slow. To calculate a string’s width it can’t call len on the string. Instead it has to pass every character through a state machine.
Option 2: For very localized changes, it might even re-evaluate all shortcuts within that one affected cluster.
。safew官方版本下载对此有专业解读
需要索引（如算距离、下标）：栈存索引，用 nums[stack.at(-1)] 取值比较。
Eleanor LawsonWest Midlands