LeetCode 算法题【Medium】：3. Longest Substring Without Repeating Characters

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链接：https://leetcode.com/problems/longest-substring-without-repeating-characters/

Question

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

Example 1:

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

Example 2:

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

Example 3:

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Input: s = "pwwkew"
Output: 3
Explanation: 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.

My Answer

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var lengthOfLongestSubstring = function(s) {
    const strArr = s.split('')
    const arrLen = strArr.length
    const letterCnt = new Set(strArr).size
   if (letterCnt === 1) return 1
    if (letterCnt === arrLen) return s.length
    for(let strLen = letterCnt; strLen > 0; strLen--) {
        for (let startIdx = 0; startIdx <= arrLen - strLen; startIdx ++) {
            const str = s.slice(startIdx, startIdx + strLen)
            const arr = str.split('')
            if (arr.length === new Set(arr).size) {
                return str.length
            }
        }
    }
    return result.length
};