Encryption and decryption of tinyurl in leetcode

subject

TinyURL It's a kind of URL Simplify services , such as ： When you enter a URL https://leetcode.com/problems/design-tinyurl when , It will return a simplified URL http://tinyurl.com/4e9iAk . Please design a class to encrypt and decrypt TinyURL .

There is no limit to how encryption and decryption algorithms are designed and operated , You just need to guarantee one URL Can be encrypted into a TinyURL , And this TinyURL It can be restored to the original by decryption URL .

Realization Solution class ：

Solution() initialization TinyURL System object .
String encode(String longUrl) return longUrl Corresponding TinyURL .
String decode(String shortUrl) return shortUrl The original URL . The subject data guarantees a given shortUrl Is encrypted by the same system object .

Example ：

Input ：url = “https://leetcode.com/problems/design-tinyurl”
Output ：“https://leetcode.com/problems/design-tinyurl”

explain ：
Solution obj = new Solution();
string tiny = obj.encode(url); // Returns the result of encryption TinyURL .
string ans = obj.decode(tiny); // Returns the original after decryption URL .

Tips ：

1 <= url.length <= 10^4
Topic data assurance url Is an effective URL

source ： Power button （LeetCode）

Their thinking

   In the medium question, this is a relatively simple question , There are many ways to encrypt and decrypt , Generally, you can add a string that can be mapped directly after a given string , It can be randomly generated or fixed , Here, for simplicity, you can directly use a simple increasing subscript .

class Codec:

    def __init__(self):
        self.n=0
        self.webset=dict()

    def encode(self, longUrl: str) -> str:
        """Encodes a URL to a shortened URL. """
        self.webset[self.n]=longUrl
        return 'http://tinyurl.com/'+str(self.n)
        

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

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