# ---
# title: 1371. Find the Longest Substring Containing Vowels in Even Counts
# id: problem1371
# author: Tian Jun
# date: 2020-10-31
# difficulty: Medium
# categories: String
# link: <https://leetcode.com/problems/find-the-longest-substring-containing-vowels-in-even-counts/description/>
# hidden: true
# ---
# 
# Given the string `s`, return the size of the longest substring containing each
# vowel an even number of times. That is, 'a', 'e', 'i', 'o', and 'u' must
# appear an even number of times.
# 
# 
# 
# **Example 1:**
# 
#     
#     
#     Input: s = "eleetminicoworoep"
#     Output: 13
#     Explanation: The longest substring is "leetminicowor" which contains two each of the vowels: **e** , **i** and **o** and zero of the vowels: **a** and **u**.
#     
# 
# **Example 2:**
# 
#     
#     
#     Input: s = "leetcodeisgreat"
#     Output: 5
#     Explanation: The longest substring is "leetc" which contains two e's.
#     
# 
# **Example 3:**
# 
#     
#     
#     Input: s = "bcbcbc"
#     Output: 6
#     Explanation: In this case, the given string "bcbcbc" is the longest because all vowels: **a** , **e** , **i** , **o** and **u** appear zero times.
#     
# 
# 
# 
# **Constraints:**
# 
#   * `1 <= s.length <= 5 x 10^5`
#   * `s` contains only lowercase English letters.
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
