535. Encode and Decode TinyURL

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. Design a class to encode a URL and decode a tiny URL.
There is no restriction on how your encode/decode algorithm should work. You just need to ensure that a URL can be encoded to a tiny URL and the tiny URL can be decoded to the original URL.
Implement the Solution class:
  • Solution() Initializes the object of the system.
  • String encode(String longUrl) Returns a tiny URL for the given longUrl.
  • String decode(String shortUrl) Returns the original long URL for the given shortUrl. It is guaranteed that the given shortUrl was encoded by the same object.
Example 1:
Input: url = "https://leetcode.com/problems/design-tinyurl"
Solution obj = new Solution();
string tiny = obj.encode(url); // returns the encoded tiny url.
string ans = obj.decode(tiny); // returns the original url after deconding it.
  • 1 <= url.length <= 10^4
  • url is guranteed to be a valid URL.


type Codec struct {
count int
func Constructor() Codec {
return Codec{ count: 0 }
// Encodes a URL to a shortened URL.
func (this *Codec) encode(longUrl string) string {
newStr := longUrl + " "
return newStr
// Decodes a shortened URL to its original URL.
func (this *Codec) decode(shortUrl string) string {
return shortUrl[:len(shortUrl) - 1]
* Your Codec object will be instantiated and called as such:
* obj := Constructor();
* url := obj.encode(longUrl);
* ans := obj.decode(url);