0070-simplify_path.py

"""
https://leetcode.com/problems/simplify-path/

You are given an absolute path for a Unix-style file system, which
always begins with a slash '/'. Your task is to transform this
absolute path into its simplified canonical path.

Example 1:
Input: path = "/home/"
Output: "/home"
Explanation:
The trailing slash should be removed.

Example 2:
Input: path = "/home//foo/"
Output: "/home/foo"
Explanation:
Multiple consecutive slashes are replaced by a single one.

Example 3:
Input: path = "/home/user/Documents/../Pictures"
Output: "/home/user/Pictures"
Explanation:
A double period ".." refers to the directory up a level (the parent directory).

Example 4:
Input: path = "/../"
Output: "/"
Explanation:
Going one level up from the root directory is not possible.

Example 5:
Input: path = "/.../a/../b/c/../d/./"
Output: "/.../b/d"
Explanation:
"..." is a valid name for a directory in this problem.
"""

import re


class Solution:
    def simplifyPath(self, path: str) -> str:
        dirs = []
        for dir in re.split(r"/+", path):
            if dir == "." or dir == "":
                next
            elif dir == "..":
                if len(dirs) > 0:
                    dirs.pop()
            else:
                dirs.append(dir)

        return "/" + "/".join(dirs)


print(Solution().simplifyPath("/home/"))
# /home
print(Solution().simplifyPath("/home//foo/"))
# /home/foo
print(Solution().simplifyPath("/home/user/Documents/../Pictures"))
# /home/user/Pictures
print(Solution().simplifyPath("/../"))
# /
print(Solution().simplifyPath("/.../a/../b/c/../d/./"))
# /.../b/d