How do you solve Simplify Path on LeetCode?

Simplify Path (LeetCode #71) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(n) space complexity. Key insight: Understanding how to manipulate strings and manage directory structures is crucial.

What is the brute force solution for Simplify Path?

The brute force approach for Simplify Path is Brute Force, with O(n²) time complexity and O(1) space complexity. The brute force approach involves splitting the path string into components, processing each component, and reconstructing the path. This method is straightforward but inefficient due to repeated operations. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Simplify Path?

Simplify Path uses the following concepts: String, Stack. The recommended patterns to study are: Stack, String Manipulation.

What are the interview tips for Simplify Path?

Always clarify the problem requirements and constraints before jumping into coding. Think about edge cases and how your solution handles them. Explain your thought process clearly while coding to demonstrate your understanding.

What are common mistakes when solving Simplify Path?

Failing to handle multiple consecutive slashes properly. Not considering edge cases like paths that lead to the root directory.

#71

Simplify Path

Medium

StringStackStackString Manipulation

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n)
Space	O(1)	O(n)

💡

Intuition

Time O(n)Space O(n)

The optimal solution uses a stack to efficiently manage the directory components. This approach processes each component exactly once, making it much faster.

⚙️

Algorithm

4 steps

1Step 1: Split the input path by '/' to get all components.
2Step 2: Initialize an empty stack to keep track of valid directory names.
3Step 3: Iterate through each component and handle '.', '..', and valid directory names.
4Step 4: After processing all components, join the stack to form the simplified path.

solution.py12 lines

1def simplifyPath(path):
2    parts = path.split('/')
3    stack = []
4    for part in parts:
5        if part == '' or part == '.':
6            continue
7        if part == '..':
8            if stack:
9                stack.pop()
10        else:
11            stack.append(part)
12    return '/' + '/'.join(stack)

ℹ

Complexity note: The complexity is O(n) because we process each component of the path exactly once, and the space complexity is O(n) due to the stack storing the valid directory names.

1Understanding how to manipulate strings and manage directory structures is crucial.
2Using a stack helps efficiently manage the directory levels.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.