"""

Longest Absolute File Path

Given a string representing a file system in a special format, find the

length of the longest absolute path to a file. Directories and files

are separated by newlines; depth is indicated by tab characters.

Reference: https://leetcode.com/problems/longest-absolute-file-path/

Complexity:

Time: O(n)

Space: O(d) where d is the maximum depth

"""

from __future__ import annotations

def length_longest_path(input_str: str) -> int:

"""Find the length of the longest absolute path to a file.

Args:

input_str: A string encoding the file system structure using

newlines and tabs.

Returns:

Length of the longest absolute path to a file, or 0 if no file exists.

Examples:

>>> length_longest_path("dir\\n\\tfile.txt")

12

"""

current_length = 0

max_length = 0

stack: list[int] = []

for segment in input_str.split("\n"):

depth = segment.count("\t")

while len(stack) > depth:

current_length -= stack.pop()

name_length = len(segment.strip("\t")) + 1

stack.append(name_length)

current_length += stack[-1]

if "." in segment:

max_length = max(max_length, current_length - 1)

return max_length