Encode and Decode TinyURL — LeetCode 535 Python Solution

The problem

Note: This is a companion problem to the System Design problem: Design TinyURL. TinyURL is a URL shortening service where you enter a URL such as https://leetcode.com/problems/design-tinyurl and it returns a short URL such as http://tinyurl.com/4e9iAk.

Example

Input

url = "https://leetcode.com/problems/design-tinyurl"

Output

"https://leetcode.com/problems/design-tinyurl"

Explanation

Solution obj = new Solution();

Python solution

class Codec:
    def __init__(self):
        self.m = defaultdict()
        self.idx = 0
        self.domain = 'https://tinyurl.com/'

    def encode(self, longUrl: str) -> str:
        """Encodes a URL to a shortened URL."""
        self.idx += 1
        self.m[str(self.idx)] = longUrl
        return f'{self.domain}{self.idx}'

    def decode(self, shortUrl: str) -> str:
        """Decodes a shortened URL to its original URL."""
        idx = shortUrl.split('/')[-1]
        return self.m[idx]


# Your Codec object will be instantiated and called as such:
# codec = Codec()
# codec.decode(codec.encode(url))

Complexity

Pattern: Hash Map

Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 535. Encode and Decode TinyURL is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Hash Table.

The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.

Related problems