#211 Longest Substring Without Repeating Characters

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javascript

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string

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Write a function that takes a string s and returns the length of the longest possible substring that has no duplicate characters.

A substring refers to any continuous part of the original string, formed by taking a sequence of consecutive characters.

Constraints:

0 ≤ s.length ≤ 5 × 10⁴
s consists of English letters, digits, symbols and spaces

Examples:

// Example 1:

const s1 = "abcabcbb";
console.log(lengthOfLongestSubstring(s1));
// Output: 3

// Explanation: The answer is "abc", with the length of 3.


// Example 2:

const s2 = "bbbbb";
console.log(lengthOfLongestSubstring(s2));
// Output: 1

// Explanation: The answer is "b", with the length of 1.


// Example 3:

const s3 = "pwwkew";
console.log(lengthOfLongestSubstring(s3));
// Output: 3

// Explanation: The answer is "wke", with the length of 3.

// Note that "pwke" is a subsequence and not a substring.