Update README.md

Author: assassint2017

README.md

@@ -2,6 +2,10 @@
 [comment]:分割线的加入方式：----
 
 # leetcode-algorithm
+|total|easy|medium|hard|
+|:---:|:---:|:---:|:---:|
+|83|23|50|10|
+
 1. [Two Sum](https://github.com/assassint2017/leetcode-algorithm/tree/master/Two%20Sum)
 2. [Add Two Numbers](https://github.com/assassint2017/leetcode-algorithm/tree/master/Add%20Two%20Numbers)
 3. [Longest Substring Without Repeating Characters](https://github.com/assassint2017/leetcode-algorithm/tree/master/Longest%20Substring%20Without%20Repeating%20Characters)