340. Longest Substring with At Most K Distinct Characters

Given a string, find the length of the longest substring T that contains at most k distinct characters.

Example 1: 

Input: 

s = 
"eceba"

, k = 
2

Output: 

3

Explanation: 

T is "ece" which its length is 3.

Example 2: 

Input: 

s = 
"aa"

, k = 
1

Output: 

2
Explanation: 

T is "aa" which its length is 2.

Difficulty:

Hard

Lock:

Prime

Company:

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Solution(Chinese):

LEETCODE 340. Longest Substring with At Most K Distinct Characters 解题思路分析