Update 217._contains_duplicate.md

Author: 0xkookoo

docs/Leetcode_Solutions/217._contains_duplicate.md

@@ -1,14 +1,40 @@
-### 217. Contains Duplicate
+#  217. Contains Duplicate
+**<font color=red>难度: 简单</font>**
 
-题目:
-<https://leetcode.com/problems/contains-duplicate/>
+## 刷题内容
 
+> 原题连接
 
-难度:
+* https://leetcode.com/problems/contains-duplicate/
 
-Easy 
+> 内容描述
+
+```
+
+Given an array of integers, find if the array contains any duplicates.
+
+Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct.
+
+Example 1:
+
+Input: [1,2,3,1]
+Output: true
+Example 2:
+
+Input: [1,2,3,4]
+Output: false
+Example 3:
+
+Input: [1,1,1,3,3,4,3,2,4,2]
+Output: true
+```
+
+## 解题方案
+
+> 思路 1
+
+利用set怎么可以这么简单。。。。
 
-怎么可以这么简单。。。。
 
 ```python
 class Solution(object):
@@ -21,6 +47,7 @@ class Solution(object):
 ```
 
 
+> 思路 2
 
 或者先 sort 也可以