Readme update

Author: tech-cow

README.md

@@ -1 +1,19 @@
 # LeetCode
+# [LeetCode](https://leetcode.com/problemset/algorithms/) ![Language](https://img.shields.io/badge/language-Python%20%2F%20C++%2011-orange.svg) [![License](https://img.shields.io/badge/license-MIT-blue.svg)](./LICENSE.md) ![Progress](https://img.shields.io/badge/progress-468%20%2F%20468-ff69b4.svg)
+
+Up to date (2016-12-18), there are `447` Algorithms / `13` Database / `4` Shell / `4` Draft questions on [LeetCode Online Judge](https://leetcode.com/).
+The number of questions is increasing recently.
+Here is the classification of all `468` questions.
+For more questions and solutions, you can see my [LintCode](https://github.com/kamyu104/LintCode) repository.
+I'll keep updating for full summary and better solutions. Stay tuned for updates.
+(Notes: "📖" means you need to subscribe to [LeetCode premium membership](https://leetcode.com/subscribe/) for the access to premium questions.)
+
+## Algorithms
+
+* [Linked List](https://github.com/kamyu104/LeetCode#linked-list)
+
+
+## Linked List
+|  #  | Title | Solution | Time | Space | Difficulty |Tag| Note|
+|-----|-------| -------- | ---- | ------|------------|---|-----|
+|2|[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/) | [C++](./C++/add-two-numbers.cpp) [Python](./Python/add-two-numbers.py) | _O(n)_| _O(1)_  | Medium | lala| lala|