Simplify Path | Problems

Given an absolute Unix-style file path, simplify it to its canonical form.

Rules: "." refers to the current directory, ".." moves up one directory, multiple consecutive slashes are treated as a single slash, and any trailing slash is removed. The result always starts with a single "/".

Examples

Input: path = "/home/"
Output: "/home"

Input: path = "/home//foo/"
Output: "/home/foo"

Input: path = "/a/./b/../../c/"
Output: "/c"

Input: path = "/../"
Output: "/"
Explanation: Can't go above root.

Constraints

1 <= path.length <= 3000
path consists of English letters, digits, '.', '/', or '_'.

Sample Input

path = "/home/"

Sample Output

"/home"

Constraints

1 <= path.length <= 3000
path consists of English letters, digits, period, slash, or underscore

Test Cases

Case 1

Args: ["/home/"] Expected: "/home"

Topics

String Hash Table

Split the path by "/" and process each component using a stack. Skip empty strings and ".". For "..", pop the stack (if non-empty). Everything else gets pushed. Join the remaining stack elements with "/" at the end.

function simplifyPath(path) {
  const stack = [];
  const parts = path.split('/');

  for (const part of parts) {
    if (part === '' || part === '.') continue;
    if (part === '..') {
      stack.pop();
    } else {
      stack.push(part);
    }
  }

  return '/' + stack.join('/');
}

Time: O(n) where n is the length of the path string. Space: O(n) for the stack in the worst case.

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