23-Simplify-Path.md

Simplify Path

Problem Link

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

---

Pattern

• Stack
• String

---

Approach

Split the path by slash, ignore dots, and use a stack to process directory names.

---

Time Complexity

O(n)

Space Complexity

O(n)

---

Java Solution

import java.util.*;
class Solution {
    public String simplifyPath(String path) {
        Stack<String> stack = new Stack<>();
        for (String part : path.split("/")) {
            if (part.equals("") || part.equals(".")) continue;
            if (part.equals("..")) {
                if (!stack.isEmpty()) stack.pop();
            } else {
                stack.push(part);
            }
        }
        StringBuilder ans = new StringBuilder();
        for (String dir : stack) ans.append('/').append(dir);
        return ans.length() == 0 ? "/" : ans.toString();
    }
}