Last updated on October 6th, 2024 at 08:35 pm

Here, We see Longest Absolute File Path LeetCode Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc. with different approaches.

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Longest Absolute File Path LeetCode Solution

Problem Statement

Suppose we have a file system that stores both files and directories. An example of one system is represented in the following picture:

Here, we have dir as the only directory in the root. dir contains two subdirectories, subdir1 and subdir2. subdir1 contains a file file1.ext and subdirectory subsubdir1. subdir2 contains a subdirectory subsubdir2, which contains a file file2.ext.

In text form, it looks like this (with ⟶ representing the tab character):dir ⟶ subdir1 ⟶ ⟶ file1.ext ⟶ ⟶ subsubdir1 ⟶ subdir2 ⟶ ⟶ subsubdir2 ⟶ ⟶ ⟶ file2.ext

If we were to write this representation in code, it will look like this: “dir\n\tsubdir1\n\t\tfile1.ext\n\t\tsubsubdir1\n\tsubdir2\n\t\tsubsubdir2\n\t\t\tfile2.ext”. Note that the ‘\n’ and ‘\t’ are the new-line and tab characters.

Every file and directory has a unique absolute path in the file system, which is the order of directories that must be opened to reach the file/directory itself, all concatenated by ‘/’s. Using the above example, the absolute path to file2.ext is “dir/subdir2/subsubdir2/file2.ext”. Each directory name consists of letters, digits, and/or spaces. Each file name is of the form name.extension, where name and extension consist of letters, digits, and/or spaces.

Given a string input representing the file system in the explained format, return the length of the longest absolute path to a file in the abstracted file system. If there is no file in the system, return 0.

Note that the testcases are generated such that the file system is valid and no file or directory name has length 0.

Example 1:

Input: input = “dir\n\tsubdir1\n\tsubdir2\n\t\tfile.ext”
Output: 20
Explanation: We have only one file, and the absolute path is “dir/subdir2/file.ext” of length 20.

Example 2:

Input: input = “dir\n\tsubdir1\n\t\tfile1.ext\n\t\tsubsubdir1\n\tsubdir2\n\t\tsubsubdir2\n\t\t\tfile2.ext”
Output: 32
Explanation: We have two files: “dir/subdir1/file1.ext” of length 21 “dir/subdir2/subsubdir2/file2.ext” of length 32. We return 32 since it is the longest absolute path to a file.

Example 3:
Input: input = “a”
Output: 0
Explanation: We do not have any files, just a single directory named “a”.

1. Longest Absolute File Path LeetCode Solution C++

class Solution {
public:
    int lengthLongestPath(string input) {
        deque<int> dq;
        int len = 0, res = 0, level = 0;
        bool file = false;
        for(char c: input){
            if(c == '\n'){
                dq.push_back(len);
                level = len = file = 0;
            }
            else if(c == '\t') ++level;
            else if(c == '.') ++len, file = true;
            else{
                ++len;
                if(file) res = max(res, len + accumulate(dq.begin(), dq.end(), 0) + level);
                while(level < dq.size()){
                    dq.pop_back();
                }
            }
        }        
        return res;
    }
};

2. Longest Absolute File Path LeetCode Solution Java

class Solution {
    public int lengthLongestPath(String input) {
        String[] lines = input.split("\n");
        int maxLength = 0;
        HashMap<Integer, Integer> pathLengths = new HashMap<>();
        for (String line : lines) {
            String name = line.replaceAll("\t", "");
            int depth = line.length() - name.length();
            boolean isFile = name.contains(".");
            if (isFile) {
                maxLength = Math.max(maxLength, pathLengths.get(depth) + name.length());
            } else {
                pathLengths.put(depth + 1, pathLengths.getOrDefault(depth, 0) + name.length() + 1);
            }
        }
        return maxLength;
    }
}

3. Longest Absolute File Path LeetCode Solution JavaScript

var lengthLongestPath = function(input) {
    let dir = input.split('\n');
    let max = 0;
    let length = [];
    let depth= 0;
    for (let i=0;i<dir.length;i++) {
        depth = dir[i].lastIndexOf('\t')+1;
        if (dir[i].includes('.')) {
            let fileLength = dir[i].length-depth;
            max = Math.max((length[depth-1]+1||0) + fileLength , max);
        } else {
            length[depth] = dir[i].length - depth + (length[depth-1]+1||0);
        }
    }
    return max;
};

4. Longest Absolute File Path LeetCode Solution Python

class Solution(object):
    def lengthLongestPath(self, input):
        lines = input.split('\n')
        max_length = 0
        path_lengths = {0: 0}
        for line in lines:
            name = line.lstrip('\t')
            depth = len(line) - len(name)
            is_file = '.' in name
            if is_file:
                max_length = max(max_length, path_lengths[depth] + len(name))
            else:
                path_lengths[depth + 1] = path_lengths[depth] + len(name) + 1
        return max_length