Normalize an Absolute Unix-Style File Path to Canonical Form

You are given an absolute path in a Unix-style file system. Rewrite it in canonical form by resolving the special directory names and removing redundant separators. ### Function Signature ```python def canonicalize_path(path: str) -> str: ``` ### Rules - The input always starts with `/`. Split it into components on `/`; any run of consecutive slashes counts as a single separator, and empty components are ignored. - A component equal to `.` refers to the current directory and is dropped. - A component equal to `..` moves up to the parent directory, removing the most recently kept name. At the root there is no parent, so `..` leaves the path at the root. - Every other component is an ordinary directory or file name, including names made only of periods such as `...` or `....`. - The canonical path starts with exactly one `/`, joins the kept names with single `/` characters, and has no trailing `/`. If no names remain, the result is `/`. ### Constraints - `1 <= len(path) <= 3000` - `path[0] == "/"` - `path` contains only English letters, digits, `.`, `/` and `_`. ### Examples **Example 1** ```text Input: path = "/usr//local/./bin/" Output: "/usr/local/bin" ``` The doubled slash collapses, the `.` component is dropped and the trailing slash is removed. **Example 2** ```text Input: path = "/a/b/../../../c/.../d/.." Output: "/c/..." ``` The first two `..` components undo `b` and `a`; the third is applied at the root and has no effect. `...` is an ordinary name, and the final `..` undoes `d`. **Example 3** ```text Input: path = "/../" Output: "/" ```