Update 3._Longest_Substring_Without_Repeating_Characters.md

Author: 0xkookoo

docs/Leetcode_Solutions/Java/3._Longest_Substring_Without_Repeating_Characters.md

@@ -1,11 +1,40 @@
+# 3. Longest Substring Without Repeating Characters
 
-### 3. Longest Substring Without Repeating Characters
+**<font color=red>难度: Medium</font>**
 
-题目:
-https://leetcode.com/problems/longest-substring-without-repeating-characters/
+## 刷题内容
 
-难度:
-Medium
+> 原题连接
+
+* https://leetcode.com/problems/longest-substring-without-repeating-characters/description/
+
+> 内容描述
+
+```
+Given a string, find the length of the longest substring without repeating characters.
+
+Example 1:
+
+Input: "abcabcbb"
+Output: 3 
+Explanation: The answer is "abc", with the length of 3. 
+Example 2:
+
+Input: "bbbbb"
+Output: 1
+Explanation: The answer is "b", with the length of 1.
+Example 3:
+
+Input: "pwwkew"
+Output: 3
+Explanation: The answer is "wke", with the length of 3. 
+             Note that the answer must be a substring, "pwke" is a subsequence and not a substring.
+```
+
+## 解题方案
+
+> 思路 1
+******- 时间复杂度: O(N)******- 空间复杂度: O(1)******
 
 ```java
 class Solution {
@@ -20,4 +49,4 @@ class Solution {
         return maxLen;
     }
 }
-```java
+```