adding Problem 36

Author: aQua

Algorithms/0036.valid-sudoku/README.md

@@ -1,7 +1,15 @@
 # [36. Valid Sudoku](https://leetcode.com/problems/valid-sudoku/)
 
 ## 题目
+Determine if a Sudoku is valid, according to: [Sudoku Puzzles - The Rules.](http://sudoku.com.au/TheRules.aspx)
 
+The Sudoku board could be partially filled, where empty cells are filled with the character '.'.
+![sudoku](sudoku.png)
+
+A partially filled sudoku which is valid.
+
+Note:
+A valid Sudoku board (partially filled) is not necessarily solvable. Only the filled cells need to be validated.
 
 ## 解题思路