## Question

Given a string s, find the length of the longest substring without repeating characters.

**Example 1:**

Input:s = "abcabcbb"Output:3Explanation:The answer is "abc", with the length of 3.

**Example 2:**

Input:s = "bbbbb"Output:1Explanation:The answer is "b", with the length of 1.

**Example 3:**

Input:s = "pwwkew"Output:3Explanation:The answer is "wke", with the length of 3. Notice that the answer must be a substring, "pwke" is a subsequence and not a substring.

**Constraints:**

`0 <= s.length <= 5 * 10`

^{4}`s`

consists of English letters, digits, symbols and spaces.

## Python Solution

class Solution: def lengthOfLongestSubstring(self, A: str) -> int: i = j = result = 0 sz = len(A) storage = set() while i < sz and j < sz: if A[j] in storage: storage.remove(A[i]) i += 1 else: storage.add(A[j]) j += 1 result = max(result, j-i) return (result)